Compositions and process for liquid scintillation counting

International Nuclear Information System (INIS)

1974-01-01

Liquid scintillation counting compositions which include certain polyethoxylated poly(oxypropylene) emulsifiers allow stable dispersion of aqueous or other samples merely by shaking. Preferred are mixtures of such emulsifiers which give homogeneous monophasic-appearing dispersions over wide ranges of temperature and aqueous sample content. Certain of these emulsifiers, without being mixed, are of particular advantage when used in analysis of samples obtained through radioimmunoassay techniques which are extremely difficult to disperse. Certain of these emulsifiers, also without being mixed, uniformly give homogeneous monophasic-appearing aqueous counting samples over much wider ranges of aqueous sample content and temperature than prior sample emulsifiers

Some studies on extractive liquid scintillation counting for Th-234/P-234m

International Nuclear Information System (INIS)

Grudpan, K.; Singjanusong, P.; Punyodom, W.

1990-01-01

A study on solvent extraction for Th-234/Pa-234m by liquid scintillation counting has not been reported. This paper will report an application of the technique on such a study. In a hydrochloric acid solution of an uranyl salt, Pa-234m which is one of the daughters of U-238 can be separated by extraction into isobutyl methyl ketone (IBMK). Cerenkov counting was applied for the extraction investigation. Solvent extraction of Th-234/Pa-234m from an aqueous nitric acid solution by TOPO/PPO in toluene by using liquid scintillation counting will be described

Liquid scintillation counting of 3H-thymidine incorporated into rat lens DNA

International Nuclear Information System (INIS)

Soederberg, P.G.; Lindstroem, B.

1990-01-01

DNA synthesis in the lens has previously been localized by autoradiography following incorporation of 3 H-thymidine. For the quantification of DNA synthesis in the lens, pooling of lenses and extraction of the DNA for liquid scintillation counting, has formerly been adapted. In the present investigation a method has been developed for the extraction of the unincorporated tracer from whole lenses after short time incubation in a medium containing 3 H-thymidine. The 3 H-thymidine incorporated into individual lenses was then detected by liquid scintillation counting after dissolution of the lenses. The sources of the variation in the method are evaluated. (author)

Poissonian and binomial models in radionuclide metrology by liquid scintillation counting

International Nuclear Information System (INIS)

Grau Malonda, A.

1990-01-01

Binomial and Poissonian models developed for calculating the counting efficiency from a free parameter is analysed in this paper. This model have been applied to liquid scintillator counting systems with two or three photomultipliers. It is mathematically demostrated that both models are equivalent and that the counting efficiencies calculated either from one or the other model are identical. (Author)

Assay of /sup 32/Si by liquid scintillation counting

Energy Technology Data Exchange (ETDEWEB)

Cumming, J B [Brookhaven National Lab., Upton, NY (USA)

1983-10-03

Application of the radioactivity of /sup 32/Si to problems of interest in geo- and cosmo-chemistry has been hampered by uncertainties in the half-life of this nuclide. A procedure for the stimulation assay of /sup 32/Si and its /sup 32/P daughter utilizing a liquid scintillation detector in association with a pulse height analyzer is described. The results indicate that /sup 32/Si can be assayed to an accuracy of a few percent by liquid scintillation counting techniques which do not require the preparation of an organic Si derivative. Combination of the mean specific activity with the /sup 32/Si abundance determined by accelerator-based mass spectrometry gave the reported 101+-18 year half-life.

Current status of liquid scintillation counting

International Nuclear Information System (INIS)

Klingler, G.W.

1981-01-01

Scintillation counting of alpha particles has been used since the turn of the century. The advent of pulse shape discrimination has made this method of detection accurate and reliable. The history, concepts and development of scintillation counting and pulse shape discrimination are discussed. A brief look at the ongoing work in the consolidation of components now used for pulse shape discrimination is included

Method for determination of radon-222 in water by liquid scintillation counting

International Nuclear Information System (INIS)

Suomela, J.

1993-06-01

The procedure for the determination of radon-222 by liquid scintillation counting is quite specific for this radionuclide. Radon-222 is extracted readily from the water sample by an organic scintillant. The decay products of radon-222 will remain in the water phase whilst radon-222 will be extracted into the organic phase. Before measurement the sample is stored for three hours until equilibrium is reached between radon-222 and its alpha emitting decay products. The alpha activity from radon-222 and its decay products is measured in a liquid scintillation counter

Liquid scintillation counting efficiency in three photomultiplier systems. Pure electron capture

International Nuclear Information System (INIS)

Los Arcos, J. M.; Grau Carles, A.; Grau Malonda, A.

1990-01-01

The tables of counting efficiency as a function of the figure of merit for a liquid scintillation counting system working with three phototubes are presented. The evaluation has been carried out for a Toluene-based scintillator with 5, 10 and 15 ml column, and 19 different radionuclides decaying by pure electron capture: 37Ar 41Ca, 49V, 53 Mn, 55Fe, 59Ni, 68Ge 7iGe, 82Sr, 97Tc, 118Te, 131CS, 137La, 140Ca, 157Tb, 165Er, 193Pt, 194Hg, 205Pb. (Author) 22 refs

PMP, a novel solute for liquid and plastic scintillation counting

International Nuclear Information System (INIS)

Gusten, Hans

1983-01-01

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

Cherenkov radiation effects on counting efficiency in extremely quenched liquid scintillation samples

International Nuclear Information System (INIS)

Grau Carles, A.; Grau Malonda, A.; Rodriguez Barquero, L.

1993-01-01

The CIEMAT/NIST tracer method has successfully standardized nuclides with diverse quench values and decay schemes in liquid scintillation counting. However, the counting efficiency is computed inaccurately for extremely quenched samples. This article shows that when samples are extremely quenched, the counting efficiency in high-energy beta-ray nuclides depends principally on the Cherenkov effect. A new technique is described for quench determination, which makes the measurement of counting efficiency possible when scintillation counting approaches zero. A new efficiency computation model for pure beta-ray nuclides is also described. The results of the model are tested experimentally for 89 Sr, 90 Y, 36 Cl and 204 Tl nuclides with independence of the quench level. (orig.)

Counting efficiency for liquid scintillator systems with a single multiplier phototube

International Nuclear Information System (INIS)

Grau Malonda, A.; Garcia-Torano, E.

1984-01-01

In this paper counting efficiency as a function of a free parameter (the figure of merit) has been computed. The results are applicable to liquid scintillator systems with a single multiplier phototube. Tables of counting efficiency for 62 pure beta emitters are given for figures of merit in the range 0.25 to 50. (Author) 16 refs

Liquid scintillation counting standardization of Na129I by the CIEMAT/NIST method

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

1996-01-01

We describe a sample preparation procedure for liquid scintillation measurements of stable solution of Na''129I. The counting stability and spectral evolution of this solution is studied in HiSafe''tmII, Ultima-Gold''tm and Insta-Gel''r. The liquid scintillation measurements have been carried efficiencies lower than 0.4%. the solution has been standardized in terms of activity concentration to an overall uncertainty of 0.46% (k=1 )

Determination of Np, Pu and Am in high level radioactive waste with extraction-liquid scintillation counting

International Nuclear Information System (INIS)

Yang Dazhu; Zhu Yongjun; Jiao Rongzhou

1994-01-01

A new method for the determination of transuranium elements, Np, Pu and Am with extraction-liquid scintillation counting has been studied systematically. Procedures for the separation of Pu and Am by HDEHP-TRPO extraction and for the separation of Np by TTA-TiOA extraction have been developed, by which the recovery of Np, Pu and Am is 97%, 99% and 99%, respectively, and the decontamination factors for the major fission products ( 90 Sr, 137 Cs etc.) are 10 4 -10 6 . Pulse shape discrimination (PSD) technique has been introduced to liquid scintillation counting, by which the counting efficiency of α-activity is >99% and the rejection of β-counts is >99.95%. This new method, combining extraction and pulse shape discrimination with liquid scintillation technique, has been successfully applied to the assay of Np, Pu and Am in high level radioactive waste. (author) 7 refs.; 7 figs.; 4 tabs

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Evaluation of oxidation techniques for preparing bioassay and environmental samples for liquid scintillation counting

International Nuclear Information System (INIS)

Miller, H.H.

1979-10-01

In environmental and biological monitoring for carbon-14 and tritium, the presence of color and chemical quenching agents in the samples can degrade the efficiency of liquid scintillation counting. A series of experiments was performed to evaluate the usefulness, under routine conditions, of first oxidizing the samples to improve the counting by removing the color and quenching agents. The scintillation counter was calibrated for the effects of quenching agents on its counting efficiency. Oxidizing apparatus was tested for its ability to accurately recover the 14 C and 3 H in the samples. Scintillation counting efficiences were compared for a variety of oxidized and unoxidized environmental and bioassay samples. The overall conclusion was that, for routine counting, oxidation of such samples is advantageous when they are highly quenched or in solid form

Compositions and process for liquid scintillation counting

International Nuclear Information System (INIS)

Kauffman, J.M.

1976-01-01

Liquid scintillation counting compositions which include certain polyethoxylated poly(oxypropylene) emulsifiers allow stable dispersion of aqueous or other samples merely by shaking. Preferred are mixtures of such emulsifiers, which give homogeneous, monophasic-appearing dispersions over wide ranges of temperature and aqueous sample content. Certain of these emulsifiers, without being mixed, are of particular advantage when used in analysis of samples obtained through radioimmunoassay techniques, which are extremely difficult to disperse. Certain of these emulsifiers, also without being mixed, uniformly give homogeneous, monophasic appearing aqueous couting samples over much wider ranges of aqueous sample content and temperature than prior sample emulsifiers

Compositions and process for liquid scintillation counting

International Nuclear Information System (INIS)

Kauffman, J.M.

1978-01-01

Liquid scintillation compositions which include certain polyethoxylated poly(oxypropylene) emulsifiers allow stable dispersion of aqueous or other samples merely by shaking. Preferred are mixtures of such emulsifiers, which give homogeneous, monophasic-appearing dispersions over wide ranges of temperature and aqueous sample content. Certain of these emulsifiers, without being mixed, are of particular advantage when used in analysis of samples obtained through radioimmunoassay techniques, which are extremely difficult to disperse. Certain of these emulsifiers, also without being mixed, uniformly give homogeneous, monophasic appearing aqueous counting samples over much wider ranges of aqueous sample content and temperature than prior sample emulsifiers

Chemical and colour quenching in liquid scintillation counting

International Nuclear Information System (INIS)

Grau Malonda, A.; Scott Guilleard, P.E.

1986-01-01

Chemical and colour quenching for H-3 and C-14 was studied. The method includes spectral analysis of colouring agents; methyl red (4'-dimethylamine-azobenzene 2-carboxilic acid) dimethyl yellow (4'-dimethylamine-azobenzene) and melachite green (metane, bis (4'-dimethyl aminophenyl)-(phenyl)). External standard channels ratio was applied for the liquid scintillation counting of samples. The introduction of an isolated external standard seems to be a strong tool for the correction of chemical and colour quenching curves. (author). 10 figs., 12 refs

Chemical and colour quenching in liquid scintillation counting

International Nuclear Information System (INIS)

Scott G, P. E.; Grau M, A.

1987-01-01

Chemical and colour quenching for H-3 and C-14 was studied. The method includes spectral analysis of colouring agents; methyl red, (4'-dimethylamine-azobenzene 2-carboxylic acid) dimethyl yellow (4'-dimethylamine-azobenzene) and malachite green (methane, bis .(4-dimethyl aminophenyl) - (phenyl)). External standard channels ratio was applied for the liquid scintillation counting of samples. The introduction of an isolated external standard seems to be a strong tool for the correction of chemical and colour quenching curves. (Author) 12 refs

Efficiency calibration of a liquid scintillation counter for 90Y Cherenkov counting

International Nuclear Information System (INIS)

Vaca, F.; Garcia-Leon, M.

1998-01-01

In this paper a complete and self-consistent method for 90 Sr determination in environmental samples is presented. It is based on the Cherenkov counting of 90 Y with a conventional liquid scintillation counter. The effects of color quenching on the counting efficiency and background are carefully studied. A working curve is presented which allows to quantify the correction in the counting efficiency depending on the color quenching strength. (orig.)

Liquid scintillation counting analysis of cadmium-109

International Nuclear Information System (INIS)

Robinson, M.K.; Barfuss, D.W.

1991-01-01

Recently the authors have used radiolabled cadmium-109 to measure the transport of inorganic cadmium in renal proximal tubules. An anomaly discovered in the liquid scintillation counting analysis of Cd-109 which is not attributable to normal decay; it consists of a significant decrease in the measured count rate of small amounts of sample. The objective is to determine whether the buffer solution used in the membrane transport studies is causing precipitation of the cadmium or whether cadmium is being adsorbed by the glass. It was important to determine whether the procedure could be modified to correct this problem. The problem does not appear to be related to the use of the buffer or to adsorption of Cd onto glass. Correction based on using triated L-glucose in all of these experiments and calculating a correction factor for the concentration of cadmium

Study on determination of 90Sr by liquid scintillation spectrometry

International Nuclear Information System (INIS)

Zhai Xiufang; Li Weiping; Tian Mei; Zou Ronghu

2012-01-01

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

Comparison of the efficacy of biodegradable and non-biodegradable scintillation liquids on the counting of tritium- and [14C]-labeled compounds

Directory of Open Access Journals (Sweden)

Medeiros R.B.

2003-01-01

Full Text Available The widespread use of ³H and 14C in research has generated a large volume of waste mixed with scintillation liquid, requiring an effective control and appropriate storage of liquid radioactive waste. In the present study, we compared the efficacy of three commercially available scintillation liquids, Optiphase HiSafe 3, Ultima-Gold(TM AB (biodegradable and Insta-Gel-XF (non-biodegradable, in terms of [14C]-glucose and [³H]-thymidine counting efficiency. We also analyzed the effect of the relative amount of water (1.6 to 50%, radioisotope concentration (0.1 to 100 nCi/ml, pH (2 to 10 and color of the solutions (samples containing 0.1 to 1.0 mg/ml of Trypan blue on the counting efficiency in the presence of these scintillation liquids. There were few significant differences in the efficiency of 14C and ³H counting obtained with biodegradable or non-biodegradable scintillation liquids. However, there was an 83 and 94% reduction in the efficiency of 14C and ³H counting, respectively, in samples colored with 1 mg/ml Trypan blue, but not with 0.1 mg/ml, independent of the scintillation liquid used. Considering the low cost of biodegradable scintillation cocktails and their efficacy, these results show that traditional hazardous scintillation fluids may be replaced with the new safe biodegradable fluids without impairment of ³H and 14C counting efficiency. The use of biodegradable scintillation cocktails minimizes both human and environmental exposure to hazardous solvents. In addition, some biodegradable scintillation liquids can be 40% less expensive than the traditional hazardous cocktails.

Applications of liquid scintillation tubes

International Nuclear Information System (INIS)

Broga, D.W.

1977-01-01

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

A new method of quench monitoring in liquid scintillation counting

International Nuclear Information System (INIS)

Horrocks, D.L.

1978-01-01

The quench level of different liquid scintillation counting samples is measured by comparing the responses (pulse heights) produced by the same energy electrons in each sample. The electrons utilized in the measurements are those of the maximum energy (Esub(max)) which are produced by the single Compton scattering process for the same energy gamma-rays in each sample. The Esub(max) response produced in any sample is related to the Esub(max) response produced in an unquenched, sealed standard. The difference in response on a logarithm response scale is defined as the ''H Number''. The H number is related to the counting efficiency of the desired radionuclide by measurement of a set of standards of known amounts of the radionuclide and different amounts of quench (standard quench curve). The concept of the H number has been shown to be theoretically valid. Based upon this proof, the features of the H number concept as embodied in the Beckman LS-8000 Series Liquid Scintillation Systems have been demonstrated. It has been shown that one H number is unique; it provides a method of instrument calibration and wide dynamic quench range measurements. Further, it has been demonstrated that the H number concept provides a universal quench parameter. Counting efficiency vs. H number plots are repeatable within the statistical limits of +-1% counting efficiency. By the use of the H number concept a very accurate method of automatic quench compensation (A.Q.C.) is possible. (T.G.)

Study on quench effects in liquid scintillation counting during tritium measurements

International Nuclear Information System (INIS)

Ivana Jakonic; Jovana Nikolov; Natasa Todorovic; Miroslav Veskovic; Branislava Tenjovic

2014-01-01

Quench effects can cause a serious reduction in counting efficiency for a given sample/cocktail mixture in liquid scintillation counting (LSC) experiments. This paper presents a simple experiment performed in order to test the influence of quenching on the LSC efficiency of 3 H. The aim of this study was to investigate the behavior of several quench agents with different quench strengths (nitromethane, nitric acid, acetone, dimethyl-sulfoxide) added in different amounts to tritiated water in order to obtain standard sets for quench calibration curves. The OptiPhase HiSafe 2 and OptiPhase HiSafe 3 scintillation cocktails were used in this study in order to compare their quench resistance. Measurements were performed using a low-level LS counter (Wallac, Quantulus 1220). (author)

Fitting of alpha-efficiency versus quenching parameter by exponential functions in liquid scintillation counting

International Nuclear Information System (INIS)

Sosa, M.; Manjón, G.; Mantero, J.; García-Tenorio, R.

2014-01-01

The objective of this work is to propose an exponential fit for the low alpha-counting efficiency as a function of a sample quenching parameter using a Quantulus liquid scintillation counter. The sample quenching parameter in a Quantulus is the Spectral Quench Parameter of the External Standard (SQP(E)), which is defined as the number of channel under which lies the 99% of Compton spectrum generated by a gamma emitter ( 152 Eu). Although in the literature one usually finds a polynomial fitting of the alpha counting efficiency, it is shown here that an exponential function is a better description. - Highlights: • We have studied the quenching in alpha measurement by liquid scintillation counting. • We have reviewed typical fitting of alpha counting efficiency versus quenching parameter. • Exponential fitting of data is proposed as better fitting. • We consider exponential fitting has a physical basis

Fitting of alpha-efficiency versus quenching parameter by exponential functions in liquid scintillation counting

Energy Technology Data Exchange (ETDEWEB)

Sosa, M. [Departamento de Ingeniería Física, Campus León, Universidad de Guanajuato, 37150 León, Guanajuato (Mexico); Universidad de Sevilla, Departamento de Física Aplicada II, E.T.S. Arquitectura, Av. Reina Mercedes, 2, 41012 Sevilla (Spain); Manjón, G., E-mail: manjon@us.es [Universidad de Sevilla, Departamento de Física Aplicada II, E.T.S. Arquitectura, Av. Reina Mercedes, 2, 41012 Sevilla (Spain); Mantero, J.; García-Tenorio, R. [Universidad de Sevilla, Departamento de Física Aplicada II, E.T.S. Arquitectura, Av. Reina Mercedes, 2, 41012 Sevilla (Spain)

2014-05-01

The objective of this work is to propose an exponential fit for the low alpha-counting efficiency as a function of a sample quenching parameter using a Quantulus liquid scintillation counter. The sample quenching parameter in a Quantulus is the Spectral Quench Parameter of the External Standard (SQP(E)), which is defined as the number of channel under which lies the 99% of Compton spectrum generated by a gamma emitter ({sup 152}Eu). Although in the literature one usually finds a polynomial fitting of the alpha counting efficiency, it is shown here that an exponential function is a better description. - Highlights: • We have studied the quenching in alpha measurement by liquid scintillation counting. • We have reviewed typical fitting of alpha counting efficiency versus quenching parameter. • Exponential fitting of data is proposed as better fitting. • We consider exponential fitting has a physical basis.

Accurate disintegration-rate measurement of 55Fe by liquid scintillation counting

International Nuclear Information System (INIS)

Steyn, J.; Oberholzer, P.; Botha, S.M.

1979-01-01

A method involving liquid scintillation counting is described for the accurate measurement of disintegration rate of 55 Fe. The method is based on the use of calculated efficiency functions together with either of the nuclides 54 Mn and 51 Cr as internal standards for measurement of counting efficiencies by coincidence counting. The method was used by the NAC during a recent international intercomparison of radioactivity measurements, and a summary of the results obtained by nine participating laboratories is presented. A spread in results of several percent is evident [af

The ionization quench factor in liquid-scintillation counting standardizations

CERN Document Server

Grau-Malonda, A

1999-01-01

We present a new detailed analysis of the ionization quench function Q(E) used in calculating the counting efficiency in liquid-scintillation counting (LSC), which shows that Q(0)=1, and permits one to derive Q(E) as a function of the electron energy and the parameter kB. The coefficients are tabulated by applying a new empirical formula of Q(E) for kB values in the range between 0.001 and 0.20 gMeV sup - sup 1 cm sup - sup 2. We demonstrate the convenience of applying sup 3 H and sup 5 sup 4 Mn for beta-ray and electron capture standardizations, respectively.

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

International Nuclear Information System (INIS)

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

2012-01-01

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. - Highlights: ► We standardized the positron emitter Ga-68 in a bilateral cooperation. ► We used several techniques, as coincidence, integral gamma and liquid scintillation. ► An efficiency comparison replaced a direct comparison of reference materials.

Simple analytical technique for liquid scintillation counting of environmental carbon-14 using gel suspension method

International Nuclear Information System (INIS)

Okai, Tomio; Wakabayashi, Genichiro; Nagao, Kenjiro; Matoba, Masaru; Ohura, Hirotaka; Momoshima, Noriyuki; Kawamura, Hidehisa

2000-01-01

A simple analytical technique for liquid scintillation counting of environmental 14 C was developed. Commercially available gelling agent, N-lauroyl-L -glutamic -α,γ-dibutylamide, was used for the gel-formation of the samples (gel suspension method) and for the subsequent liquid scintillation counting of 14 C in the form of CaCO 3 . Our procedure for sample preparation is much simpler than that of the conventional methods and requires no special equipment. Self absorption, stability and reproducibility of gel suspension samples were investigated in order to evaluate the characteristics of the gel suspension method for 14 C activity measurement. The self absorption factor is about 70% and slightly decrease as CaCO 3 weight increase. This is considered to be mainly due to the absorption of β-rays and scintillation light by the CaCO 3 sample itself. No change of the counting rate for the gel suspension sample was observed for more than 2 years after the sample preparation. Four samples were used for checking the reproducibility of the sample preparation method. The same values were obtained for the counting rate of 24 C activity within the counting error. No change of the counting rate was observed for the 're-gelated' sample. These results show that the gel suspension method is appropriate for the 14 C activity measurement by the liquid scintillation counting method and useful for a long-term preservation of the sample for repeated measurement. The above analytical technique was applied to actual environmental samples in Fukuoka prefecture, Japan. Results obtained were comparable with those by other researchers and appear to be reasonable. Therefore, the newly developed technique is useful for the routine monitoring of environmental 14 C. (author)

Standardization of iodine-129 by the TDCR liquid scintillation method and 4π β-γ coincidence counting

Science.gov (United States)

Cassette, P.; Bouchard, J.; Chauvenet, B.

1994-01-01

Iodine-129 is a long-lived fission product, with physical and chemical properties that make it a good candidate for evaluating the environmental impact of the nuclear energy fuel cycle. To avoid solid source preparation problems, liquid scintillation has been used to standardize this nuclide for a EUROMET intercomparison. Two methods were used to measure the iodine-129 activity: triple-to-double-coincidence ratio liquid scintillation counting and 4π β-γ coincidence counting; the results are in good agreement.

Liquid scintillation alpha spectrometry techniques

International Nuclear Information System (INIS)

McKlveen, J.W.; McDowell, W.J.

1984-01-01

Accurate, quantitative determinations of alpha emitting nuclides by conventional plate counting methods are difficult, because of sample self-absorption problems in counting and because of non-reproducible losses in conventional sample separation methods. Liquid scintillation alpha spectrometry offers an attractive alternative with no sample self-absorption or geometry problems and with 100% counting efficiency. Sample preparation may include extraction of the alpha emitter of interest by a specific organic phase-soluble compound directly into the liquid scintillation counting medium. Detection electronics use energy and pulse-shape discrimination, to yield alpha spectra without beta and gamma background interference. Specific procedures have been developed for gross alpha, uranium, plutonium, thorium and colonium assay. Possibilities for a large number of other applications exist. Accuracy and reproducibility are typically in the 1% range. Backgrounds of the order of 0.01 cpm are readily achievable. The paper will present an overview of liquid scintillation alpha counting techniques and some of the results achieved for specific applications. (orig.)

Liquid Scintillation counting Standardization of 22 NaCl by the CIEMAT/NIST method

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

1995-09-01

We describe a procedure for preparing a stable solution of ''22 NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4/% and an overall uncertainty of 0.35%

Comparison of accelerator mass spectrometric measurement with liquid scintillation counting measurement for the determination of 14C in environmental samples

International Nuclear Information System (INIS)

Yasuike, Kaeko; Yamada, Yoshimune; Amano, Hikaru

2010-01-01

The concentrations of organically-bound 14 C in tree-ring cellulose of a Japanese Black Pine grown in Shika-machi (37.0 deg. N, 136.8 deg. E) and those of a Japanese Cedar grown in Kanazawa (36.5 deg. N, 136.7 deg. E), Japan, were analyzed for the ring-years from 1989 to 1998 by the accelerator mass spectrometric measurement. The results were compared with those of the same samples analyzed by the liquid scintillation counting measurement to determine the reliability of liquid scintillation counting measurement. An important result of this study is that the sensitivity and reproducibility of accelerator mass spectrometric measurement was almost equal to that of liquid scintillation counting measurement.

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

International Nuclear Information System (INIS)

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.

Determination of plutonium-241 by liquid scintillation counting method and its application to environmental samples

International Nuclear Information System (INIS)

Watanabe, Miki; Amano, Hikaru

1997-03-01

Radionuclides are usually measured by gross counting mode in liquid scintillator counting (LSC) which measures both α and β pulses. This method can easily measure radioactivities, but its background counting is high. Recently reported α-β pulse shape discrimination method (α-β PSD method) in LSC which distinguishes α pulses from β pulses, shows low background counting, so it makes the detection limit lower. The aim of this research is to develop the best method for the determination of 241 Pu which is β-emitter, and Pu isotopes of α-emitters which have long half-lives and stay long in animal body. In this research, two LSC machines was carried out in different scintillators, vial volumes, measurement modes and so on. The following things were found. 1. The liquid scintillator based on naphthalene is proved to be the best separator of α-ray from β-ray, because it acts quickly in energy translation procedure between solvent and aromatic compounds. 2. α-β PSD method makes the background counting rate ten times lower than usual method. It makes the measurement performance better. 3. It is possible to determine 241 Pu in environmental samples around Chernobyl by the combination of LSC and radiochemical separation methods. (author)

Triton X-100 as a complete liquid scintillation cocktail for counting aqueous solutions and ionic nutrient salts

International Nuclear Information System (INIS)

Reed, D.W.

1984-01-01

Triton X-100, used alone, was found to act as a complete liquid scintillation cocktail. Triton X-100 acted as a scintillator and the effect was not due to Cerenkov radiation. A variety of other commercially available surfactants also acted as scintillators, but with different levels of efficiency. Triton X-100/water combinations were suitable for counting aqueous solutions of 33 P and 86 Rb and the count rate was stable over extended periods of time. Triton X-100/toluene combinations also yielded high counting efficiencies. Triton X-100 was more sensitive to quenching than standard cocktails containing fluors. (author)

Upgradation of automatic liquid scintillation counting system

International Nuclear Information System (INIS)

Bhattacharya, Sadhana; Behere, Anita; Sonalkar, S.Y.; Vaidya, P.P.

2001-01-01

This paper describes the upgradation of Microprocessor based Automatic Liquid Scintillation Counting systems (MLSC). This system was developed in 1980's and subsequently many systems were manufactured and supplied to Environment Survey labs at various Nuclear Power Plants. Recently this system has been upgraded to a more sophisticated one by using PC add-on hardware and developing Windows based software. The software implements more intuitive graphical user interface and also enhances the features making it comparable with commercially available systems. It implements data processing using full spectrum analysis as against channel ratio method adopted earlier, improving the accuracy of the results. Also it facilitates qualitative as well as quantitative analysis of the β-spectrum. It is possible to analyze a sample containing an unknown β-source. (author)

Liquid Scintillation Counting Standardization of 22NaCl by te CIEMAT/NIST method

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

1995-01-01

We describe a procedure for preparing a stable solution of ''22NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4 % and an overall uncertainty of 0.35 %. (Author) 4 refs

Radioactivity measurement of barium carbonate [14C] by liquid scintillation counting

International Nuclear Information System (INIS)

Kobayashi, Katsutoshi; Hoizumi, Kiyoshi

1985-03-01

Two methods of sample preparation for the measurement of specific activity of BaCO 3 [ 14 C] by external standard method in liquid scintillation counting were studied. BaCO 3 [ 14 C] was decomposed by perchloric acid solution and generated CO 2 [ 14 C] was absorbed by ethylene glycol monomethyl ether solution of monoethanolamine as the method 1 or aqueous sodium hydroxide as the method 2. In order to prepare the sample solution of adequate radioactivity concentration, these carbonate solutions by the methods 1 and 2 were diluted with the suitable organic solvent and distilled water respectively. One tenth millilitre of these sample solutions was added into 10 ml of PPO-toluene scintillator containing 0.1 ml of monoethanolamine in a counting vial and homogeneously dissolved with ethyl alcohol. The results of the radioactivity measurement of BaCO 3 [ 14 C] based on the different method agreed within 5 % and the counting rate was found to be stable for as long as 7 deays or more. Both methods of preparation are suitable for the routine measurement because of their simplicity and feasibility. In the case of method 2, the liquid radioactive waste is almost inorganic solution and recovery in the form of BaCO 3 [ 14 C] is easily performed, so that this method is very advantageous from the view point of the radioactive waste treatement. (author)

Study of alternative methods for the management of liquid scintillation counting wastes

International Nuclear Information System (INIS)

Roche-Farmer, L.

1980-02-01

The Nuclear Engineering Waste Disposal Site in Richland, Washington, is the only radioactive waste disposal facility that will accept liquid scintillation counting wastes (LSCW) for disposal. That site is scheduled to discontinue receiving LSCW by the end of 1982. This document explores alternatives presently available for management of LSCW: evaporation, distillation, solidification, conversion, and combustion

Scinfi, a program to calculate the standardization curve in liquid scintillation counting

International Nuclear Information System (INIS)

Grau Carles, A.; Grau Malonda, A.

1984-01-01

A code, Scinfi, was developed, written in Basic, to compute the efficiency-quench standardization curve for any radionuclide. The program requires the standardization curve for 3 H and the polynomial relations between counting efficiency and figure of merit for both 3 H and the problem (e.g. 14 C). The program is applied to the computation of the efficiency-quench standardization curve for 14 C. Five different liquid scintillation spectrometers and two scintillator solutions have been checked. The computation results are compared with the experimental values obtained with a set of 14 C standardized samples. (author)

SCINFI, a program to calculate the standardization curve in liquid scintillation counting

International Nuclear Information System (INIS)

Grau Carles, A.; Grau Malonda, A.

1984-01-01

A code, SCINFI, was developed, written in BASIC, to compute the efficiency- quench standardization curve for any radionuclide. The program requires the standardization curve for 3H and the polynomial relations between counting efficiency and figure of merit for both 3H and the problem (e.g. 14 C ). The program is applied to the computation of the efficiency-quench standardization curve for 14 c . Five different liquid scintillation spectrometers and two scintillator solutions have bean checked. The computation results are compared with the experimental values obtained with a set of 14 c standardized samples. (Author)

Standardization of {sup 241}Am by digital coincidence counting, liquid scintillation counting and defined solid angle counting

Energy Technology Data Exchange (ETDEWEB)

Balpardo, C., E-mail: balpardo@cae.cnea.gov.a [Laboratorio de Metrologia de Radioisotopos, CNEA, Buenos Aires (Argentina); Capoulat, M.E.; Rodrigues, D.; Arenillas, P. [Laboratorio de Metrologia de Radioisotopos, CNEA, Buenos Aires (Argentina)

2010-07-15

The nuclide {sup 241}Am decays by alpha emission to {sup 237}Np. Most of the decays (84.6%) populate the excited level of {sup 237}Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of {sup 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.

Role of quenching on alpha/beta separation in liquid scintillation counting for several high capacity cocktails

International Nuclear Information System (INIS)

Pujol, L.; Sanchez-Cabeza, J.-A.

1997-01-01

The optimization of alpha/beta separation in liquid scintillation using pulse shape analysis is convenient for the simultaneous determination of alpha and beta emitters in natural water and other samples. In this work, alpha/beta separation was studied for different scintillant/vial combinations and it was observed that both the optimum pulse shape discrimination level and the total interference value (that is, the summed relative interference between alpha and beta spectra) were dependent on the sample quenching and independent of the scintillant/vial combination. These results provide a simple method for modifying the counting configuration, such as a change in the cocktail, vial or sample characteristics, without the need to perform exhaustive parameter optimizations. Also, it was observed that, for our counting conditions, the combination of Ultima Gold AB scintillation cocktail with Zinsser low diffusion vials presented the lowest total interference, namely 0.94 ± 0.28%, which is insignificant for the counting of environmental samples. (Author)

Correct liquid scintillation counting of steroids and glycosides in RIA samples: a comparison of xylene-based, dioxane-based and colloidal counting systems. Chapter 14

International Nuclear Information System (INIS)

Spolders, H.

1977-01-01

In RIA, the following parameters are important for accurate liquid scintillation counting. (1) Absence of chemiluminescence. (2) Stability of count rate. (3) Dissolving properties for the sample. For samples with varying colours, a quench correction must be applied. For any type of accurate quench correction, a homogeneous sample is necessary. This can be obtained if proteins and the buffer can be dissolved completely in the scintillator solution. In this paper, these criteria are compared in xylene-based, dioxane-based and colloidal scintillation solutions for either bound or free antigens of different polarity. The labelling radioisotope used was 3 H. Using colloidal scintillators with plasma and buffer samples, phasing or sedimentation of salt or proteins sometimes occurs. The influence of sedimentation or phasing on count rate stability and correct quench correction is illustrated by varying the ratio between the scintillator solution and a RIA sample containing a semi-polar steroid aldosterone. (author)

A new analytical method for 32P. Liquid scintillation counting with solvent extraction

International Nuclear Information System (INIS)

Liyanage, J.A.; Yonezawa, C.

2003-01-01

Trace determination of phosphorus has been studied using neutron activation analysis. Radioactivity of 32 P in tri-n-octylamine phosphomolybdate complex was measured using liquid scintillation counting by extracting the complex into xylene. Phosphorus can be quantitatively determined from 16.7 to 600 μg/10 ml by using the radiochemical analysis method described. (author)

Determination of 226Ra and 224Ra in drinking waters by liquid scintillation counting

International Nuclear Information System (INIS)

Manjon, G.; Vioque, I.; Moreno, H.; Garcia-Tenorio, R.; Garcia-Leon, M.

1997-01-01

A method for the determination of Ra-isotopes in water samples has been developed. Ra is coprecipitated with Ba as sulphate. The precipitate is then dissolved with EDTA and counted with a liquid scintillation system after mixing with a scintillation cocktail. The study of the temporal evolution of the separated activity gives the isotopic composition of the sample, i.e. the 224 Ra and 226 Ra contribution to the total activity. The method has been applied to some Spanish drinking waters. (author)

Liquid scintillation in medical diagnosis

International Nuclear Information System (INIS)

Painter, K.

1976-01-01

With the tremendous increase in the application of radioassay, particularly radioimmunoassay, in the clinical laboratory liquid scintillation counting became an indispensable tool in diagnostic medicine. Few publications, however, have concerned themselves with problem areas which occur with the method in the clinical laboratory. The purpose of this presentation is to summarize our experiences with the liquid scintillation technique in the clinical situation

Analytical method of Kr-85 determination, using cryogenic concentration and separation and liquid scintillation counting

International Nuclear Information System (INIS)

Heras Iniquez, M.C.; Perez Garcia, M.M.; Grau Malonda, A.

1983-01-01

The method used in the Laboratory of the JEN for the determination of Kr-85 levels in gaseous effluents of nuclear power and in the atmosphere is described. Samples of air, collected in metallic cylinders, are introduced into a gas-solid chromatographic separation system which resolves Kr from the other air components. The separated Kr ia dissolved in a toluene based scintillation cocktail, and the Kr-85 content is determined by liquid scintillation counting. (Author)

Sample oxidation for liquid scintillation counting

International Nuclear Information System (INIS)

Kisieleski, W.E.; Buess, E.M.

1976-01-01

The general features of biological and medical investigations which are responsible for the demands such investigations place upon the design specifications of liquid scintillation counters and associated methodology are reviewed. Special emphasis is given to the oxidative technique for sample preparation

Liquid organic scintillator in a polymerizable emulsion, its application to radioactive counting and process for its destruction

International Nuclear Information System (INIS)

O'Brien, R.E.; Krieger, J.K.

1981-01-01

Scintillation organic liquid mixture for performing very efficient counts on compound solutions labelled with a radioactive indicator containing up to 10% water by volume and which is easily polymerizable into a solid substance, in order to facilitate its elimination. The mixture includes a polymerizable organic solvent, a solubilizing agent, an intermediate solvent and an organic scintillator [fr

The determination of Pu-241 by liquid scintillation counting in liquid effluents of the Karlsruhe Nuclear Research Center

International Nuclear Information System (INIS)

Godoy, J.M.; Schuettelkopf, H.; Pimpl, M.

1983-04-01

A procedure was developed to measure Pu-241 by liquid scintillation counting. Sample preparation was performed by electroplating of plutonium on stainless steel planchets. To correct the selfabsorption, the linear dependence of counting efficiency in the liquid scintillation counter from the resolution in the alpha spectrometer was used. Pu-238, Pu-239+240 and Pu-241 were measured in the liquid effluents of the Karlsruhe Nuclear Research Center (KfK). The concentrations in monthly mixed samples ranged from 0.07 until 46 nCi Pu-238/m 3 , from 0.13 until 2.1 nCi Pu-239+240/m 3 and from 25 until 190 nCi Pu-241/m 3 . Between 5.4% and 41% of the plutonium content of the KfK waste water are released to the River Old Rhine. The values for the activity ratio Pu-238/Pu-239+240 are between 0.39 and 1.1 and for Pu-241/Pu-239+240 are between 11 and 300. The mean value for Pu-241/Pu-239+240 is 61. The dose exposure of the environmental population of the Karlsruhe Nuclear Research Center caused by released Pu-241 is negligible low. (orig./HP) [de

Review of the evolution of safety, ecological and economical aspects of liquid scintillation counting materials and techniques

International Nuclear Information System (INIS)

Kalbhen, D.A.

1983-01-01

The wide applicability of liquid scintillation techniques for counting weak β-emitters and other radionuclides has led to the daily use of a large number of liquid scintillation counter instruments in research and control laboratories. Of the solvents used in liquid scintillators, xylene, toluene and trimethyl benzene are most common. To a minor extent, dioxane, methylglycol, ethanol and methanol are also used. The estimated annual total volume is around 2-3 million liters of scintillation cocktails. The present situation demonstrates a problem in laboratory safety and concomitant cost for waste treatment, usually not recognized. The use and handling of these inflammable and irritant solvents can induce certain risks to personnel and laboratory safety. A significant reduction of the ecological and health risks is important. In recent years, some progress has been made by using smaller volumes and smaller sizes of vials. The introduction of non-flammable scintillator solvents, which do not penetrate through polyethylene vials and do not escape into the laboratory atmosphere, also adds to the safety process

Counting efficiencies by liquid scintillation counting. Single isomeric transitions; Eficiencia de recuento por centelleo liquido. Transiciones isomericas simples

Energy Technology Data Exchange (ETDEWEB)

Grau Carles, A.; Grau Malonda, A.

1995-07-01

In this work we present liquid scintillation counting efficiency tables for several radionuclides with single isomeric transitions, in which electron conversion and gamma emission processes are competitive. We study the radionuclides: 58mCo, 77mSe, 79mBr, 87mSr, S9mY, 93mNb, 103mRh, 107mAg, 109mAg, 113mIn, 131mXe, I33mXe, 135raBa, 137mBa, 167raEr, for two different scintillators, Ultima-Gold and Insta-Gel. We consider volumes of 10 and 15 mL for Ultima Gold, and 15 mL for Insta-Gel. (Author) 18 refs.

The efficacy of biodegradable liquid scintillation counting cocktails

International Nuclear Information System (INIS)

Klein, R.C.; Gershey, E.L.

1990-01-01

Liquid scintillation counting (LSC) waste once accounted for ∼50% of the low-level radioactive wastes generated by academic and biomedial research. Strict regulations banning the land burial of organic liquids led the U.S. Nuclear Regulatory Commission to deregulate very low level LSC waste (10CFR20.306 of the Code of Federal Regulations) in 1981. Today, LSC waste containing ≤0.05 μCi/ml of 3 H or 14 C is generally incinerated as flammable liquid. Several manufacturers are now offering cocktails that contain long-chain and multiringed aromatic compounds that have not been identified as hazardous by the Environmental Protection Agency (EPA) under the Resource Conservation and Recovery Act (40CFR261) or the Clean Water Act (40CFR122). In addition to lower toxicity and higher flash points than their predecessors, these new cocktails are being advertised as biodegradable. Simple exclusion from the relatively short EPA lists of hazardous chemicals, however, may only reflect insufficient study. Five cocktail solvent families were identified by gas chromatography (GC) and GC/mass spectrometry: meta- and ortho-xylenes, trimethylbenzene isomers, linear alkylbenzenes, 1-phenyl-1-(3,4-xylyl)-ethane, and diisopropylnaphthalene. Cocktail efficiencies were determined for tritiated samples commonly found in biomedical research by the internal standard method

Preparation of manganese salts of carboxylic acids labelled with ''54Mn and comparison with ''54 MnCl2 in liquid scintillation counting

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Arcos Merino, J. M. los; Grau Malonda, A.

1992-01-01

Procedures for liquid scintillation sample preparation of manganese dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene. HISafe II. PCS, instagel. Dioxane-naphtalene and Toluene-alcohol. For comparison, Inorganic 54 MnCl-2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (Author)

Alternating sample changer and an automatic sample changer for liquid scintillation counting of alpha-emitting materials

International Nuclear Information System (INIS)

Thorngate, J.H.

1977-08-01

Two sample changers are described that were designed for liquid scintillation counting of alpha-emitting samples prepared using solvent-extraction chemistry. One operates manually but changes samples without exposing the photomultiplier tube to light, allowing the high voltage to remain on for improved stability. The other is capable of automatically counting up to 39 samples. An electronic control for the automatic sample changer is also described

Standardization of 40 K by liquid scintillation counting. Determination of the half-life

International Nuclear Information System (INIS)

Grau Carles, A.; Grau Malonda, A.

1997-01-01

The relative abundance of the natural radioisotope ''40 K in environmental samples frequently generates interferences in low activity measurements. In the present study we propose the determination of ''40 K by the CIEMAT/NIST method. On this context, the verification of ''40 K half-life is required. We present a half-life value obtained by liquid scintillation counting in excellent agreement with those reported in the literature. (Author)

Low-level measurements by liquid scintillation counting

International Nuclear Information System (INIS)

Schoenhofer, F.

1991-01-01

Liquid scintillation counting has become a convenient tool for analysis of many beta- and alpha-emitters even in ultra low-level concentration ranges. Extremely low background is achieved in a commercially available counter by an active shielding and heavy lead shielding. Thus special time saving radiochemical separation processes could be designed. Extremely simple sample preparation techniques can be used. Counting time can be reduced and sample throughput enhanced. Also precision can be enhanced. From the author's research, several applications are discussed. They include: tritium in water without enrichment, tritium in urine (excretion analysis), carbon-14 in samples like alcohol or vinegar, Rn-222 in water and air, even gaseous Kr-85. A simple and fast method for Sr-90 in environmental samples and food has been developed and the Ra-226-concentration in water can be measured as low as 30 mBq/l without any chemical separation or enrichment. The instrument has been used successfully for screening purposes after the Chernobyl accident as well as for monitoring groundwater after a large scale contamination in Lower Austria. Using a 'gross-beta-measurement' effluents from a nuclear installation are monitored, clearly showing advantages over traditional methods. α-β-discrimination reduces the background for alpha emitters to practically zero. Examples from the determination of Ra-226 in water are shown

Planktonic primary production evaluation by means of the 14C method with liquid scintillation counting

International Nuclear Information System (INIS)

Frangopol, T.P.; Bologa, S.A.

1979-05-01

Preliminary results on the planktonic primary production obtained for the first time with the 14 C method off the Romanian Black Sea coast (1977, 1978) and in the Sinoe, Mamaia and Bicaz lakes (1978) are presented, along with a review of this method with special reference to liquid scintillation counting. 140 Refs. (author)

Rapid radiometric detection of microbial contamination using 14C-glucose and standard liquid scintillation counting system

International Nuclear Information System (INIS)

Joshi, S.H.; Kamble, S.B.; Pilkhwal, N.S.; Ramamoorthy, N.

1998-01-01

A simple and rapid method for detection of microbial contamination based on quantitation of 14 CO 2 released during metabolism of 14 C-Glucose by microorganisms is reported. Liquid scintillation counting system (LSCS) with a modified sample preparation method was utilised. The scintillator was impregnated on Whatman-1 paper on which 14 CO 2 evolved during metabolism could be absorbed. The important parameters of counting such as efficiency, position sensitivity and geometry as well as effect of NaOH quantity and of microbial load on detection period were studied. The efficiency of radioactivity assay was 18±2.8 %. Contamination of the order of 5-10 organism/ml of product could be detected in about 24 hours. (author)

Liquid scintillation counting standardization of ''125 I in organic and inorganic samples by the CIEMAT/NIST method

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J.M.; Grau Carles, A.

1994-01-01

The liquid scintillation counting standardization of organic and inorganic samples of ''125 I by the CIEMAT/NIST method using five different scintillators is described. The discrepancies between experimental and computed efficiencies are lower than 1.4% and 1.7%, for inorganic and organic samples, respectively, in the interval 421-226 of quenching parameter. Both organic and inorganic solutions have been standardized in terms of activity concentration to an overall uncertainty of 0.76%

Radioactive flow detectors: liquid or solid scintillators

International Nuclear Information System (INIS)

Reich, A.R.

1983-01-01

During the past five years, two schools of thought have emerged producing two different types of radio-HPLC detectors. Based on the naphthalene-in-the-vial principle, manufacturers have developed heterogeneous scintillation detectors. In these detectors the anthracene or naphthalene crystals are replaced by other scintillators. In order to avoid dead space and turbulence, a narrow diameter tube is used, either straight, or more popularly formed into a coil or a 'U' as the cell. To optimize light transmission to the photomultiplier tubes, mirrors are used. Due to limiting factors in this technique the counting efficiency for tritium is below the 10 percent level. The other school of radio-HPLC detectors based their design on classical liquid scintillation counting technology. In a homogeneous detector, the effluent from the HPLC system is mixed with a suitable liquid scintillator before entering the counting cell. The cell design is typically a flat glass or Teflon coil tightly sandwiched between two photomultiplier tubes, making good optical contact without the use of mirrors. Depending on the chromatographic effluent, 3 H efficiencies between 25 to 50 percent, and 14 C counting efficiencies up to 85 percent can be achieved

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

International Nuclear Information System (INIS)

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 40 K borosilicate glass vials containing 15 mL of Insta-Gel XF scintillation cocktail. Using 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- -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

Determination of 90Sr by liquid scintillation counting

International Nuclear Information System (INIS)

Cerchetti, Maria L.; Aghazarian, V.P.

2006-01-01

99m Tc, the result of the radioactive decay of 99 Mo, is one of the most applied radioisotopes in nuclear medicine and is used in nuclear medicine as a radiopharmaceutical product. It is important to ensure 99 Mo quality in order to fit the 99m Tc quality specifications. The main objective was to obtain a technique for 90 Sr determination in 99 Mo and environmental samples. The purification of 90 Sr is performed by extraction chromatography where crown-ether resin (Sr-Spec, Eichrom) was used. The measurement of the 90 Sr activity is performed by Liquid Scintillation Counting (LSC) using the double windows method. This method permits the 90 Sr determination without waiting until radiochemical equilibrium 90 Sr / 90 Y has been reached. The recovery factor was determined by gamma spectrometry with 85 Sr, and by gravimetry with stable strontium carrier solution. The minimum detectable activity was 0,05 Bq. The recovery factor was the major contribution in the total uncertainty. (author)

Determination of radon in indoor air in Quebec by liquid scintillation counting in ortho-xylene

Energy Technology Data Exchange (ETDEWEB)

Chah, B; Zikovsky, L; Champagne, P [Ecole Polytechnique, Montreal, PQ (Canada)

1992-01-01

A new method for the determination of radon in air has been developed. it is based on low temperature absorption of radon in ortho-xylene followed by liquid scintillation counting. The method is reasonably fast and sensitive enough to analyse air without precipitation. The detection limit at the 95% confidence level for a 20 l air sample and 1 h counting time is 2 mBql{sup -1}. Radon concentrations measured in indoor air in Quebec varied from 7 to 162 mBql{sup -1}. (Author).

Liquid scintillation counting standardization of 125I in organic and inorganic samples by the CIEMAT/NIST method

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

1994-01-01

The liquid scintillation counting standardization of organic and inorganic samples of ''I25I by the CIEMAT/NIST method using five different scintillators is described. The discrepancies between experimental and computed efficiencies are lower than 1.4% and 1.7%, for inorganic and organic samples, respectively, in the interval 421-226 of quenching parameter. Both organic and inorganic solutions have been standardized in terms of activity concentration to an overall uncertainty of 0.76%. (Author) 14 refs

Apparent and actual 14C retention in the slower turnover bicarbonate pool in man when using liquid scintillation counting

International Nuclear Information System (INIS)

Clague, M.B.; Keir, M.J.; Clayton, C.B.

1979-01-01

The use of liquid scintillation counting to determine 14 CO 2 expiration without correct calibration of the apparatus suggests that about 25% of the label is retained within the slower turnover bicarbonate pool. Calibration reduces this figure to 13% and is in agreement with the figure obtained using a calibrated ionisation chamber. The discrepancy is due to reduction in the specific radioactivity in the vial, the mechanism involved being unknown, but it may be a characteristic of certain liquid scintillators under certain conditions. (author)

Some history of liquid scintillator development at Los Alamos

International Nuclear Information System (INIS)

Ott, D.G.

1979-01-01

The early developments in liquid scintillation counting made at Los Alamos Scientific Laboratory are reviewed. Most of the work was under the direction of F.N. Hayes and included counter development and applications as well as synthesis and chemistry of liquid scintillators

Application of avalanche photodiodes for the measurement of actinides by alpha liquid scintillation counting

International Nuclear Information System (INIS)

Reboli, A.

2005-10-01

Alpha emitters analysis using liquid scintillation spectroscopy is often used when sensitivity and fast samples preparation are the important points. A more extensive use of this technique is until now limited by its poor resolution compared to alpha particle spectroscopy with semiconductor detectors. To improve the resolution and thus promote this method for the measurement of actinides in environment, we have tested silicon avalanche photodiodes (APD) as new detectors for scintillation photons. The set-up consists of a large area avalanche photodiode (16 mm diameter) coupled to a thin vial containing alpha-emitters within a liquid scintillation cocktail. After optimization of several parameters like bias voltage, temperature, counting geometry and composition of the scintillating cocktail, energy resolutions have been found to be better than those obtained with standard photomultiplier tubes (PMT): 5% (200 keV FWHM) for 232 Th and 4.2% (240 keV FWHM) for 236 Pu. Our results show that the improvement is due to less fluctuations associated with light collection since the spatial response of APDs is more uniform than that of PMTs. The expected gain on quantum efficiency (80% for APDs instead of 25% for PMTs) is nullified by a corresponding increase on electronic noise and excess noise factor. Significant better results are foreseen by using green scintillators (450 - 550 nm wavelengths region) with larger Stokes-shift and blue-enhanced APDs which reach their maximum quantum efficiency in this region. (author)

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

Science.gov (United States)

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

Scintillation counting: an extrapolation into the future

International Nuclear Information System (INIS)

Ross, H.H.

1983-01-01

Progress in scintillation counting is intimately related to advances in a variety of other disciplines such as photochemistry, photophysics, and instrumentation. And while there is steady progress in the understanding of luminescent phenomena, there is a virtual explosion in the application of semiconductor technology to detectors, counting systems, and data processing. The exponential growth of this technology has had, and will continue to have, a profound effect on the art of scintillation spectroscopy. This paper will review key events in technology that have had an impact on the development of scintillation science (solid and liquid) and will attempt to extrapolate future directions based on existing and projected capability in associated fields. Along the way there have been occasional pitfalls and several false starts; these too will be discussed as a reminder that if you want the future to be different than the past, study the past

Liquid emulsion scintillators which solidify for facile disposal

International Nuclear Information System (INIS)

O'Brien, R.E.; Krieger, J.K.

1981-01-01

A liquid organic scintillation cocktail is described which counts solutions of radiolabelled compounds containing up to ten % by volume of water with high efficiency and is readily polymerizable to a solid for easy disposal. The cocktail comprises a polymerizable organic solvent, a solubilizing agent, an intermediate solvent, and an organic scintillator. A method of disposing of liquid organic scintillation cocktail waste and a kit useful for practising the method are also described. (U.K.)

Spectrum library concept and pulse shape analysis in liquid scintillation counting

Energy Technology Data Exchange (ETDEWEB)

Kaihola, L [Wallac Oy, Turku (Finland)

1997-03-01

Wallac introduced in 1990 a new absolute liquid scintillation counting (LSC) method, Digital Overlay Technique (DOT) to correct for quench. This method allows quantization of multilabel samples by referring to library spectra which are generated against chemical and color quench indices at the factory. The libraries can further be expanded to any beta emitter by user with a method called fine tuning, which can be carried out even with a single sample. Spectrum libraries are created over the whole spectrum range of the radionuclide and allow automatic identification of a single label beta emitting radionuclide, called Easy Count method. Another improvement in LSC is commercial introduction of Pulse Shape Analysis (PSA) in 1986 by Wallac. This method recognizes alpha particle decay by pulse shape and leads to excellent sensitivity in alpha counting because most of the background signal in LSC comprises of short or beta like pulses. PSA detects alpha events in the presence of high excess of beta activity over alphas, up to a ratio 100000 to 1. (orig.)

The determination of Pu-241 by liquid scintillation counting in gaseous effluents of an incineration facility, FERAB, and the Karlsruhe Nuclear Reprocessing Plant, WAK

International Nuclear Information System (INIS)

Godoy, J.M.; Schuettelkopf, H.

1983-03-01

Although the concentration of Pu-241 in nuclear fuel to be reprocessed is high, there are only few results published about the emission of Pu-241 with gaseous and liquid effluents. Nearly no information is available, too, about the environmental contamination of nuclear installations by Pu-241. Therefore a procedure was developed to measure Pu-241 by liquid scintillation counting. Sample preparation was performed by electroplating of plutonium on stainless steel planchets. To correct the selfabsorption the linear dependence of counting efficiency in the liquid scintillation counter and the resolution in the α-spectrometer was used. (orig./HP) [de

Rapid determination of 226Ra in drinking water samples using dispersive liquid-liquid microextraction coupled with liquid scintillation counting

International Nuclear Information System (INIS)

Sadi, B.K.; Chunsheng Li; Kramer, G.H.; Johnson, C.L.; Queenie Ko; Lai, E.P.C.

2011-01-01

A new radioanalytical method was developed for rapid determination of 226 Ra in drinking water samples. The method is based on extraction and preconcentration of 226 Ra from a water sample to an organic solvent using a dispersive liquid-liquid microextraction (DLLME) technique followed by radiometric measurement using liquid scintillation counting. In DLLME for 226 Ra, a mixture of an organic extractant (toluene doped with dibenzo-21-crown-7 and 2-theonyltrifluoroacetone) and a disperser solvent (acetonitrile) is rapidly injected into the water sample resulting in the formation of an emulsion. Within the emulsion, 226 Ra reacts with dibenzo-21-crown-7 and 2-theonyltrifluoroacetone and partitions into the fine droplets of toluene. The water/toluene phases were separated by addition of acetonitrile as a de-emulsifier solvent. The toluene phase containing 226 Ra was then measured by liquid scintillation counting. Several parameters were studied to optimize the extraction efficiency of 226 Ra, including water immiscible organic solvent, disperser and de-emulsifier solvent type and their volume, chelating ligands for 226 Ra and their concentrations, inorganic salt additive and its concentration, and equilibrium pH. With the optimized DLLME conditions, the accuracy (expressed as relative bias, B r ) and method repeatability (expressed as relative precision, S B ) were determined by spiking 226 Ra at the maximum acceptable concentration level (0.5 Bq L -1 ) according to the Guidelines for Canadian Drinking Water Quality. Accuracy and repeatability were found to be less than -5% (B r ) and less than 6% (S B ), respectively, for both tap water and bottled natural spring water samples. The minimum detectable activity and sample turnaround time for determination of 226 Ra was 33 mBq L -1 and less than 3 h, respectively. The DLLME technique is selective for extraction of 226 Ra from its decay progenies. (author)

Age determination of trace plutonium using liquid scintillation counting and α-spectrometry

International Nuclear Information System (INIS)

Chen Yan; Chang Zhiyuan; Zhao Yonggang; Li Jinghuai; Shu Fujun

2010-01-01

Liquid scintillation counting combined with α-spectrometry through measuring 241 Pu/ 241 Am ratio to determine the age of trace Pu was studied. The technique was explored for the age determination of nanogram grade Pu sample on the basis of Pu/Am separation. The ages of two Pu samples-one with known and the other with unknown age were determined by the method. The determined age by the method is in agreement with the reference value. The established method for determining the age of trace Pu can be adopted in the verification activities of nuclear safeguards and nuclear arms control. (authors)

Determination of 90SR in food using extraction chromatography and LSC - Liquid Scintillation Counting

International Nuclear Information System (INIS)

Temba, Eliane S.C.; Amaral, Angela M.; Reis Junior, Aluisio S.; Monteiro, Roberto P.G.

2013-01-01

A methodology for the determination of 90 Sr in food is described. The procedure involved a preliminary freeze-drying of the samples followed by dry-ashing and sample digestion. The separation procedure was carried out using extraction chromatography with Sr Resin, from Eichrom, and 90 Sr was measured by liquid scintillation counting (LSC). A certified reference material, IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. The chemical yield was above 90% and the typical counting efficiency was 82%. The calculated limit of detection was 4.8 x 10 -3 Bq g -1 . (author)

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

International Nuclear Information System (INIS)

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

2015-01-01

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 ( 14 C from organically compounds, 36 Cl as chloride and free chlorine, 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 2 O 2 and KMnO 4 ), lyophilization, chemical treatment (Na 2 O 2 and KMnO 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

Measurements of 222Rn and 226Ra Levels in environmental samples by using liquid scintillation counter

International Nuclear Information System (INIS)

Moustafa, A.S.

2004-01-01

The advantageous of liquid scintillation counting technique for 6 Ra determination compared with other methods are the high counting efficiency and the easier sample preparation, with no need for sample pre-concentration. In this work, liquid scintillation counting system was used to measure 222 Rn and 226 Ra levels in environmental samples. The liquid scintillation cocktail was prepared in the laboratory and was found efficient for measuring 222 Rn. Soil, sediment and TENORM samples were dried, grind, sieved and added to hydrochloric acid, in a standard scintillation vial, preloaded with the liquid scintillation cocktail. By measuring 222 Rn levels in the prepared vials, at different intervals of time after preparation, 222 Rn and 226 Ra levels were determined

Tritium activity in milk by liquid scintillation counting

International Nuclear Information System (INIS)

Zheng Huang

1993-01-01

This paper estimates the total tritium content of both the organic and aqueous fractions simultaneously. To fulfill these conditions, the chosen scintillator should be able to accept large sample loadings and display the same counting efficiency for the organic as well as aqueous fractions of the whole milk. In an attempt to establish this method, samples from four different brands of milk were analysed using the pseudocumence based Picofluor 30 (Canberra Packard) and the di-isopropyl naphthalene based Aquasafe 500 (Zinser Analytic) scintillator solution. Glass vials were used thus enabling visual observation to be made. The tritium activities of four different brands of milks were estimated to be very low and at, or near, the detection level of the system

Preparatory on manganose salts of carboxilic acids labelled with 54Mn and comparison with 54MnCl2 in liquid scintillation counting

International Nuclear Information System (INIS)

Rodriguez, L.; Los Arcos, J.M.; Grau, A.

1992-01-01

Procedures for scintillation sample preparation of manganose dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. Their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene, HlSafe II, PCS, Instagel, Dioxane-naphtalene and Toluene-alcohol. For comparison, inorganic 54 MnCl 2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (author) 14 fig. 15 ref

Preparation of 45Ca(HDEHP)n and (CaH1502)2 samples for liquid scintillation counting, compared to 45caCl2 results

International Nuclear Information System (INIS)

Rodriguez, L.; Arcos, J. M. los; Grau Malonda, A.

1994-01-01

A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethylhexanoate calcium salt, labelled with 45Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators,Toluene-alcohol, Dioxane-naphtalene, Hi safe II, Ultimate-Gold and Instagel, and compared to results obtained from a commercial solution of 4 5CaCl2. (Author) 7 refs

Measurement of radon emanation of drainage layer media by liquid scintillation counting

International Nuclear Information System (INIS)

Turtiainen, T.

2009-01-01

Slab-on-ground is a typical base floor construction type in Finland. The drainage layer between the slab and soil is a layer of sand, gravel or crushed stone. This layer has a minimum thickness of 200 mm and is sometimes even 600 mm thick, and thus may be a significant contributor to indoor air radon. In order to investigate radon emanation from the drainage layer material, a simple laboratory test was developed. Many organic solvents have high Ostwald coefficients for radon, i.e., the ratio of the volume of gas absorbed to the volume of the absorbing liquid, which enables direct absorption of radon into a liquid scintillation cocktail. Here, we first present equations relating to the processes of gas transfer in emanation measurement by direct absorption into liquid scintillation cocktails. In order to optimize the method for emanation measurement, four liquid scintillation cocktails were assessed for their ability to absorb radon from air. A simple apparatus consisting of a closed glass container holding an open liquid scintillation vial was designed and the diffusion/absorption rate and Ostwald coefficient were determined for a selected cocktail. Finally, a simple test was developed based on this work. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Varlam, C.; Vagner, I.; Faurescu, I.; Faurescu, D. [National Institute for Cryogenics and Isotopic Technologies, Valcea (Romania)

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.

Comparison of analysis techniques by liquid scintillation and Cerenkov Effect for 40K quantification in aqueous samples

International Nuclear Information System (INIS)

Miranda C, L.; Davila R, J. I.; Lopez del R, H.; Mireles G, F.

2015-09-01

In this work the counting by liquid scintillation and Cerenkov Effect to quantify 40 K in aqueous samples was used. The performance of both techniques was studied by comparing the response of three commercial liquid scintillation OptiPhase HiSafe 3, Ultima Gold Ab and OptiPhase TriSafe, the vial type and presentation conditions of the sample for counting. In liquid scintillation, the ability to form homogeneous mixtures depended on the ionic strength of the aqueous solutions. The scintillator OptiPhase HiSafe 3 showed a greater charge capacity for solutions with high ionic strength (<3.4), while the scintillator OptiSafe TriSafe no form homogeneous mixtures for solutions of ionic strength higher than 0.3. Counting efficiencies for different proportions of sample and scintillator near 100% for the scintillators OptiSafe HiSafe 3 and Ultima Gold Ab were obtained. In the counting by Cerenkov Effect, the efficiency and sensitivity depended of the vial type; polyethylene vials were more suitable for counting that the glass vials. The sample volume had not significant effect on counting efficiency, obtaining an average value of 44.8% for polyethylene vials and 37.3% for glass vials. Therefore, the liquid scintillation was more efficient and sensitive for the measurement of 40 K in aqueous solutions. (Author)

Isolation and activity determination of 99Tc in nuclear waste by liquid scintillation counting

International Nuclear Information System (INIS)

Reis Junior, Aluisio S.; Temba, Eliane S.C.; Kastner, Geraldo F.; Monteiro, Roberto P.G.

2011-01-01

A radiochemical separation and purification for technetium was proposed for radioactive waste in which rhenium is to be used as a yield monitor. The separation was performed by anion exchange chromatography and the purification was performed by extraction chromatography using a TEVA resin.The determination of 99 Tc was by liquid scintillation counting and rhenium was activated by Triga Mark 1 research reactor and measured by gamma spectrometry. Some real samples of nuclear waste such as evaporator concentrate and filter were analysed. The chemical recovery determined using rhenium as tracer was around 90 %. (author)

New advanced in alpha spectrometry by liquid scintillation methods

International Nuclear Information System (INIS)

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

1979-01-01

Although the ability to count alpha particles by liquid scintillation methods has been long recognized, limited use has been made of the method because of problems of high background and alpha energy identification. In recent years some new developments in methods of introducing the alpha-emitting nuclide to the scintillator, in detector construction, and in electronics for processing the energy analog and time analog signals from the detector have allowed significant alleviation of the problems of alpha spectrometry by liquid scintillation. Energy resolutions of 200 to 300 keV full peak width at half maximum and background counts of 99% of all beta plus gamma interference is now possible. Alpha liquid scintillation spectrometry is now suitable for a wide range of applications, from the accurate quantitative determination of relatively large amounts of known nuclides in laboratory-generated samples to the detection and identification of very small, subpicocurie amounts of alpha emitters in environmental-type samples. Suitable nuclide separation procedures, sample preparation methods, and instrument configurations are available for a variety of analyses

Liquid Scintillation Counting - Packard Triple-Label Calibration

Energy Technology Data Exchange (ETDEWEB)

Torretto, P. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-03-23

The Radiological Measurements Laboratory (RML) maintains and operates nine Packard Liquid Scintillation Counters (LSCs). These counters were obtained through various sources and were generally purchased as 2500, 2700 or 3100 series counters. In 2004/2005 the software and firmware on the counters were upgraded. The counters are now designated as 3100 series counters running the Quantasmart software package. Thus, a single procedure can be used to calibrate and operate the Packard LSCs.

Influence of atomic and nuclear constants on the counting efficiency for 55Fe in liquid scintillators

International Nuclear Information System (INIS)

Fernandez, A.; Grau, A.; Arcos, J. M. los

1985-01-01

In this paper one considers the influence of the different parameters on the determination of the uncertainty of the detection efficiency for 55 F e when the counting technique of liquid scintillation is applied. The following parameters are considered: the relative probabilities of X and Auger emission so as their corresponding energies, the fluorescence yields W K and W L , and the non-interaction probabilities of the emitted X photons. (Author) 11 refs

Method for determining efficiency in a liquid scintillation system

International Nuclear Information System (INIS)

Laney, B.H.

1975-01-01

This invention relates to a method of counting radioactive events in a liquid scintillation radiation detecting and counting apparatus by utilizing pulses generated by a photomultiplying means resulting from scintillations caused by radioactive events. A counting efficiency value is assigned to each pulse generated in the photomultiplying means according to the height of the pulse. The numerical inverse of each assigned counting efficiency value is determined and each numerical inverse is recorded as an actual number of radioactive events with each having a pulse height identical to that of the corresponding pulse generated in the photomultiplying means. (Patent Office Record)

Radioactivity measurements by liquid scintillation spectroscopy

International Nuclear Information System (INIS)

Cassette, Ph.

2004-01-01

The activity measurement techniques by liquid scintillation spectroscopy consist to mix the radioactive solution to measure with a scintillating liquid and to transform the ionizing radiations, resulting from decays, into light, detectable and quantifiable. The main advantages of these techniques are the easiness of preparation of the radioactive sources, the geometric efficiency of detection of 4π and the possibility of detection of low-level energy radiations. There are one of the only methods giving the possibility to measure the activity of pure β radionuclides; indeed, the nuclear disintegration is not accompanied of gamma radiations detectable by other techniques. There are one of the only methods too of measurement of radionuclides which disintegrate by electron capture and especially those leading to the emission of low-level energy ionizing radiations. Liquid scintillation spectroscopy can be used as an absolute method of activity measurement that is to say without the use of a calibration standard. The modern liquid scintillation counting devices can be very sensitive; the measurement of micro-activities being possible. Some of the applications of these activity measurement techniques are the carbon 14 dating and the geological tracing. Their main disadvantage is the global energetic yield which is low and variable in terms of the composition of the scintillation source necessitating to calculate the detection yield for each condition of measurement. (O.M.)

Measurement of scintillation decay curves by a single photon counting technique

International Nuclear Information System (INIS)

Noguchi, Tsutomu

1978-01-01

An improved apparatus suitable for the measurement of spectroscopic scintillation decay curves has been developed by combination of a single photon counting technique and a delayed coincidence method. The time resolution of the apparatus is improved up to 1.16 nsec (FWHM), which is obtained from the resolution function of the system for very weak Cherenkov light flashes. Systematic measurement of scintillation decay curves is made for liquid and crystal scintillators including PPO-toluene, PBD-xylene, PPO-POPOP-toluene, anthracene and stilbene. (auth.)

Liquid scintillation cocktails comparison for tritium contamination measurements

International Nuclear Information System (INIS)

Bazzarri, S.; Belloni, P.

1996-01-01

Liquid scintillation counting is one of the most used techniques for the measurements of tritium contamination. Until few years ago a problem related to this kind of measurement was the potential toxicity of the liquid cocktails used to produce the required scintillation. Some new products that guarantee an almost negligible impact on the environment and that are no longer toxic for the operators are now available. Some of this new scintillation cocktail are suitable to be used for tritium measurement. Due to the great benefit from the health point of view of these new materials a test of their scintillation performance has been done at the ENEA centers to select the product having the best characteristics for tritium measurement. (author)

Counting efficiency for liquid scintillator systems with a single multiplier phototube; Eficiencia de recuento en espectrometros de centelleo con un solo fotomultiplicador

Energy Technology Data Exchange (ETDEWEB)

Grau Malonda, A; Garcia-Torano, E

1984-07-01

In this paper counting efficiency as a function of a free parameter (the figure of merit) has been computed. The results are applicable to liquid scintillator systems with a single multiplier phototube. Tables of counting efficiency for 62 pure beta emitters are given for figures of merit in the range 0.25 to 50. (Author) 16 refs.

New procedure for the determination of radium in water by extraction of radon and application of integral counting with a liquid scintillation counter

Energy Technology Data Exchange (ETDEWEB)

Horiuchi, K [Tokyo Metropolitan Univ. (Japan). Faculty of Science; Murakami, Y [Kitasato Univ. (Japan). School of Hygienic Sciences

1981-05-01

A new Ra determination method is devised, storing the sample in a glass bottle with a Teflon stopper in an upside-down position, extracting Rn with liquid scintillator solution and combining integral counting with a liquid scintillation counter. This method realizes a high sensitivity of 5 x 10/sup -13/ Ci Ra, eliminates the tedious procedure of transferring Rn through the vacuum system to the detector and makes possible repeated determinations of Ra on the same sample without any further chemical treatment except extraction.

Measurement of isotopic uranium in water for compliance monitoring by liquid scintillation counting with alpha/beta discrimination

International Nuclear Information System (INIS)

Venso, E.A.S.

1993-01-01

A simple and inexpensive method is described for analysis of uranium (U) activity and mass in water by liquid scintillation counting using α/β discrimination. This method appears to offer a solution to the need for an inexpensive protocol for monitoring U activity and mass simultaneously and an alternative to the potential inaccuracy involved when depending on the mass-to-activity conversion factor or activity screen. U is extracted virtually quantitatively into 20 ml extractive scintillator from a 1-ell aliquot of water acidified to less than pH 2. After phase separation, the sample is counted for a 20-minute screening count with a minimum detection level of 0.27 pCi ell -1 . α-particle emissions from the extracted U are counted with close to 100% efficiency with a Beckman LS6000 LL liquid scintillation counter equipped with pulse-shape discrimination electronics. Samples with activities higher than 10 pCi ell -1 are recounted for 500-1000 minutes for isotopic analysis. Isotopic analysis uses events that are automatically stored in spectral files and transferred to a computer during assay. The data can be transferred to a commercially available spreadsheet and retrieved for examination or data manipulation. Values for three readily observable spectral features can be rapidly identified by data examination and substituted into a simple formula to obtain 234 U/ 238 U ratio for most samples. U mass is calculated by substituting the isotopic ratio value into a simple equation. The utility of this method for the proposed compliance monitoring of U in public drinking water supplies was field tested with a survey of drinking water from Texas supplies that had previously been known to contain elevated levels of gross α activity. U concentrations in 32 samples from 27 drinking water supplies ranged from 0.26 to 65.5 pCi ell -1 , with seven samples exceeding the proposed Maximum Contaminant Level

Liquid scintillation systems and apparatus for measuring high-energy radiation emitted by samples in standard laboratory test tubes

International Nuclear Information System (INIS)

Benvenutti, R.A.

1976-01-01

Liquid scintillation detection system employs improved sample holders in which the cap of a glass vial is provided with a well for receiving a standard laboratory test tube containing a radioactive sample. The well is immersed in a liquid scintillator in the vial, the scintillator containing lead acetate solution to enhance its efficiency. A commercially available beta-counting liquid scintillation apparatus is modified to provide gamma-counting with the improved sample holders

Liquid scintillation solutions

International Nuclear Information System (INIS)

Long, E.C.

1976-01-01

The liquid scintillation solution described includes a mixture of: a liquid scintillation solvent, a primary scintillation solute, a secondary scintillation solute, a variety of appreciably different surfactants, and a dissolving and transparency agent. The dissolving and transparency agent is tetrahydrofuran, a cyclic ether. The scintillation solvent is toluene. The primary scintillation solute is PPO, and the secondary scintillation solute is dimethyl POPOP. The variety of appreciably different surfactants is composed of isooctylphenol-polyethoxyethanol and sodium dihexyl sulphosuccinate [fr

Radiation damage studies on new liquid scintillators and liquid-core scintillating fibers

International Nuclear Information System (INIS)

Golovkin, S.V.

1994-01-01

The radiation resistant of some new liquid scintillation and capillaries filled with liquid scintillators has been presented. It was found that scintillation efficiency of the scintillator based on 1-methyl naphthalene with a new R39 only by 10% at the dose of 190 Mrad and the radiation resistance of thin liquid-core scintillating was decreased fibers exceeded 60 Mrad. 35 refs

Optics study of liquid scintillation counting systems; Estudio de la Optica en sistemas de medida por centelle liquido

Energy Technology Data Exchange (ETDEWEB)

Duran Ramiro, M. T.; Garcia-Torano, E.

2005-07-01

Optics is a key issue in the development of any liquid scintillation counting (LSC) system. Light emission in the scintillating solution, transmission through the vial and reflector design are some aspects that need to be considered in detail. This paper describes measurements and calculations carried out to optimise these factors for the design of a new family of LSC counters. Measurements of the light distribution emitted by a scintillation vial were done by autoradiographs of cylindrical vials made of various materials and results were compared to those obtained by direct measurements of the light distribution made by scanning the vial with a photomultiplier tube. Calculations were also carried out to study the light transmission in the vial and the optimal design of the reflector for a system with one photomultiplier tube. (Author)

A Monte Carlo Model for Neutron Coincidence Counting with Fast Organic Liquid Scintillation Detectors

International Nuclear Information System (INIS)

Gamage, Kelum A.A.; Joyce, Malcolm J.; Cave, Frank D.

2013-06-01

Neutron coincidence counting is an established, nondestructive method for the qualitative and quantitative analysis of nuclear materials. Several even-numbered nuclei of the actinide isotopes, and especially even-numbered plutonium isotopes, undergo spontaneous fission, resulting in the emission of neutrons which are correlated in time. The characteristics of this i.e. the multiplicity can be used to identify each isotope in question. Similarly, the corresponding characteristics of isotopes that are susceptible to stimulated fission are somewhat isotope-related, and also dependent on the energy of the incident neutron that stimulates the fission event, and this can hence be used to identify and quantify isotopes also. Most of the neutron coincidence counters currently used are based on 3 He gas tubes. In the 3 He-filled gas proportional-counter, the (n, p) reaction is largely responsible for the detection of slow neutrons and hence neutrons have to be slowed down to thermal energies. As a result, moderator and shielding materials are essential components of many systems designed to assess quantities of fissile materials. The use of a moderator, however, extends the die-away time of the detector necessitating a larger coincidence window and, further, 3 He is now in short supply and expensive. In this paper, a simulation based on the Monte Carlo method is described which has been performed using MCNPX 2.6.0, to model the geometry of a sector-shaped liquid scintillation detector in response to coincident neutron events. The detection of neutrons from a mixed-oxide (MOX) fuel pellet using an organic liquid scintillator has been simulated for different thicknesses of scintillators. In this new neutron detector, a layer of lead has been used to reduce the gamma-ray fluence reaching the scintillator. The effect of lead for neutron detection has also been estimated by considering different thicknesses of lead layers. (authors)

Preparation of 45 Ca (HDEHP)n and (C8H15O2)2 samples for liquid scintillation counting, compared to 45CaCl2 results

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Los Arcos Merino, J.M.; Grau Malonda, A.

1994-01-01

A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethyhexanoate calcium salt, labelled with ''45 Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators, Toluene, Toluene-alcohol, Dioxane-napthalhene, Hisafe II, Ultima-Gold and Instagel, and compared to results obtained from a commercial solution of ''45 CaCl 2

Set of counts by scintillations for atmospheric samplings

International Nuclear Information System (INIS)

Appriou, D.; Doury, A.

1962-01-01

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

Standarization of Mn-54 by liquid scintillation counting using organic samples of (C8H15 O2)2 Mn-54

International Nuclear Information System (INIS)

1990-01-01

A new method of standardization of Mn 54 by liquid scintillation counting with an organic sample of (C 8 H 15 O 2 ) 2 Mn 54 is described. This procedure shows a good long term stability of samples, over 20 days, and counting efficiencies between 10% and 24% for PCS e INSTAGEL and 10% 32% for a toluene-based scintillator. The discrepancies between experimental and computed values are less that 0,9% for PCS and INSTAGEL and less than 1,2% for Toluene, in the 5-2,5 interval of quenching parameter. The global uncertainty on the activity concentrat-ion of a sample standardized by this method has been lower than 3% (Author)

Strontium-90 (90Sr) determination using liquid scintillation counting

International Nuclear Information System (INIS)

Cheberle, L.T.V.; Rosa, M.M.L.; Ferreira, M.T.; Taddei, M.H.T.

2015-01-01

This procedure describes a method for separation and measurement of strontium 90 Sr in water, soils, and biological samples. Water samples may be concentrated using evaporation or calcium phosphate coprecipitation. Soils and biological materials must be dissolved using wet digestion. Tracers and carriers must be added before the attack. Radioactive strontium is separated employing a specific resin before determination by liquid scintillation counting using the double energetic window method. The resin is used to concentrate strontium from samples. Stable strontium is used to monitor method yields and correct results to improve precision and accuracy. The presence of elemental strontium in the sample may bias the gravimetric yield determination. If it is suspected that natural strontium is present in the sample, its concentration should be determined by a suitable means (ICP), and the yield calculation properly modified. Sr-Spec resin with an 8M HNO 3 load solution is used to effectively remove 140 Ba and 40 K isotopes, as well as other interferences from the matrix. Tetravalent plutonium, neptunium, cerium and ruthenium, however, are not removed using nitric acid. The radiochemical procedure was tested using PROCORAD intercomparison exercises and PNI samples. (author)

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

International Nuclear Information System (INIS)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker

2015-01-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s -1 (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Ionic liquids as solvents for liquid scintillation technology. Čerenkov counting with 1-Butyl-3-Methylimidazolium Chloride

International Nuclear Information System (INIS)

Mirenda, Martín; Rodrigues, Darío; Arenillas, Pablo; Gutkowski, Karin

2014-01-01

We report the detection of the Čerenkov luminescence after the incorporation of a few droplets of a physiological solution of 2-deoxi-2( 18 F)fluorine-D-glucose into the ionic liquid 1-Butyl-3-Methylimidazolium Chloride (BmimCl). The phenomenon is attributed to the β + particles having energy above the threshold energy value for the Čerenkov radiation in this medium. The presence of another type of radiation that could eventually cause coincidences in the photodetectors was safely discarded. We show that this property serves to determine the activity of a 18 F solution by means of the novel TDCR–Čerenkov technique. The results were compared with those obtained from the classic TDCR scintillation method using a commercial scintillation cocktail. The activity values obtained from both methods were found to be virtually identical within the experimental uncertainties. The fact that high energy β particles in BmimCl generates Čerenkov photons makes this ionic liquid a promising compound for future research in detection and quantification of ionizing radiation, and it provides a potential alternative for applications in nuclear technology. - Highlights: • Čerenkov luminescence was detected when 18 F was dissolved in 1-Butyl-3-Methylimidazolium Chloride (BmimCl) ionic liquid. • The presence of another type of radiation that could eventually cause coincidences in the photodetectors was safely discarded. • Čerenkov luminescence serves to determine the activity of a 18 F solution by means of TDCR–Čerenkov technique. • Some advantages of the use of BmimCl as solvent for Čerenkov counting were listed

Manual calibration of liquid scintillation counter using the channel ratio technique

International Nuclear Information System (INIS)

Moussa, H.M.; Townsend, L.; Miller, L.F.

1999-01-01

The objectives of this activity are to introduce students to liquid scintillation counting and to calibrate the counter using the sample channel ratio technique. This is accomplished by using quenched standards set for 14 C and tritium ( 3 H) to generate a quench correction curve for the scintillation solution. It is a good method for students to gain a detailed understanding of issues important to manual calibration of a liquid scintillation counter, and results can be compared with a built-in automatic method

Rapid determination of gross alpha and beta activity in seafood utilizing microwave digestion and liquid scintillation counting

International Nuclear Information System (INIS)

Daniel Sas; Jiri Janda; Alena Tokarova

2015-01-01

This paper describes a method for rapid determination of gross alpha and beta activity in seafood using liquid scintillation counting and microwave digestion for fast sample decomposition. The general group of seafood was divided into two groups based on its structure, whether it has shell or not. The selected group of radionuclides was chosen with respect to military significance, radiotoxicity, and possibility of potential misuse. 90 Sr and 239 Pu were selected as model radionuclides. (author)

Alpha scintillation radon counting

International Nuclear Information System (INIS)

Lucas, H.F. Jr.

1977-01-01

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

Optimised method for the routine determination of Technetium-99 in environmental samples by liquid scintillation counting

International Nuclear Information System (INIS)

Wigley, F.; Warwick, P.E.; Croudace, I.W.; Caborn, J.; Sanchez, A.L.

1999-01-01

A method has been developed for the routine determination of 99 Tc in a range of environmental matrices using 99m Tc (t 1/2 =6.06 h) as an internal yield monitor. Samples are ignited stepwise to 550C and the 99 Tc is extracted from the ignited residue with 8 M nitric acid. Many contaminants are co-precipitated with Fe(OH) 3 and the Tc in the supernatant is pre-concentrated and further purified using anion exchange chromatography. Final separation of Tc from Ru is achieved by extraction of Tc into 5% tri-n-octylamine in xylene from 2 M sulphuric acid. The xylene fraction is mixed directly with a commercial liquid scintillant cocktail. The chemical yield is determined through the measurement of 99m Tc by gamma spectrometry and the 99 Tc activity is measured using liquid scintillation counting after a further two weeks to allow decay of the 99m Tc activity. Typical recoveries for this method are in the order 70-95%. The method has a detection limit of 1.7 Bq kg -1 based on a 2 h count time and a 10 g sample size. The chemical separation for 24 samples of sediment or marine biota can be completed by one analyst in a working week. A further week is required to allow the samples to decay before determination. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Liquid scintillation counting efficiency in three photomultiplier systems. Pure electron capture; Eficiencia de recuento por centelleo liquido en sistemas con tres fotomultiplicadores. Captura electronica pura

Energy Technology Data Exchange (ETDEWEB)

Los Arcos, J M; Grau Carles, A; Grau Malonda, A

1990-07-01

The tables of counting efficiency as a function of the figure of merit for a liquid scintillation counting system working with three phototubes are presented. The evaluation has been carried out for a Toluene-based scintillator with 5, 10 and 15 ml column, and 19 different radionuclides decaying by pure electron capture: 37Ar 41Ca, 49V, 53 Mn, 55Fe, 59Ni, 68Ge 7iGe, 82Sr, 97Tc, 118Te, 131CS, 137La, 140Ca, 157Tb, 165Er, 193Pt, 194Hg, 205Pb. (Author) 22 refs.

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

Energy Technology Data Exchange (ETDEWEB)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker [Mainz Univ. (Germany). Inst. fuer Kernchemie; Omtvedt, Jon-Petter [Oslo Univ. (Norway). Dept. of Chemistry; Skarnemark, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden)

2015-05-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s{sup -1} (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Method for determination of radium-226 in water by liquid scintillation counting

International Nuclear Information System (INIS)

Suomela, J.

1993-07-01

The chemical procedure involves the isolation or radium from the sample solution by co-precipitation with lead sulphate. The precipitate is dissolved in alkaline DTPA. The radium isotopes are separated from other radionuclides by co-precipitation with barium sulphate. The barium/radium precipitate is dissolved in alkaline EDTA, the solution is transfered to a liquid scintillation vial and the organic scintillant is added. After sealing, the sample is left until equilibrium between Ra-226 and Rn-222 is established or until a suitable ingrowth time has elapsed. The alpha activity of Rn-222 and its short-lived daughters, Po-218 and Po-214, are measured by the use of a commercial liquid scintillation counter. By using the following procedure and a low level LSC a lover limit of detection of 2 mBq/sample can be achieved

Estimation of low level gross alpha activities in the radioactive effluent using liquid scintillation counting technique

International Nuclear Information System (INIS)

Bhade, Sonali P.D.; Johnson, Bella E.; Singh, Sanjay; Babu, D.A.R.

2012-01-01

A technique has been developed for simultaneous measurement of gross alpha and gross beta activity concentration in low level liquid effluent samples in presence of higher activity concentrations of tritium. For this purpose, alpha beta discriminating Pulse Shape Analysis Liquid Scintillation Counting (LSC) technique was used. Main advantages of this technique are easy sample preparation, rapid measurement and higher sensitivity. The calibration methodology for Quantulus1220 LSC based on PSA technique using 241 Am and 90 Sr/ 90 Y as alpha and beta standards respectively was described in detail. LSC technique was validated by measuring alpha and beta activity concentrations in test samples with known amount of 241 Am and 90 Sr/ 90 Y activities spiked in distilled water. The results obtained by LSC technique were compared with conventional planchet counting methods such as ZnS(Ag) and end window GM detectors. The gross alpha and gross beta activity concentrations in spiked samples, obtained by LSC technique were found to be within ±5% of the reference values. (author)

Use of liquid scintillation counting for quantitative analysis of volatile organic compounds in batch isotherm analysis

International Nuclear Information System (INIS)

Wickman, D.C.

1987-01-01

An estimate of how rapidly hazardous wastes move through subsurface soils via ground water is important to predict the location and concentration of the contaminant plume vs. time. The contaminated ground water system may be viewed as an HPLC column with the organic components of the waste in adsorption/desorption equilibrium with the subsurface soil. The batch isotherm method was chosen to determine the equilibrium constant between trichloroethylene, o-dichlorobenzene, 1-methyl naphthalene and aquifer materials obtained from various locations around the country. Liquid Scintillation counting has been found to be an excellent technique for batch isotherm analysis; using 14C labeled compounds, it affords unattended analysis, accuracy at very low concentrations and rapid data reduction. Ten ml serum containing about 5 ml water and a known weight of soil (approximately 2 grams) were spiked with the labeled solution to yield organic solute concentrations in the range of 0.02-1.0 mg/1. Six different concentrations were used. After spiking, the bottles were filled to the top with water and crimp sealed with teflon coated septa. All soil containing bottles were then rotated at 50 rpm and 22 degrees Celsius. Twenty-four hours later the bottles were uncapped and a 1.4 ml aliquot was removed and placed in scintillation cocktail and counted

Activity measurements of radioactive solutions by liquid scintillation counting and pressurized ionization chambers and Monte Carlo simulations of source-detector systems for metrology

International Nuclear Information System (INIS)

Amiot, Marie-Noelle

2013-01-01

The research works 'Activity measurements of radioactive solutions by liquid scintillation and pressurized ionization chambers and Monte Carlo simulations of source-detector systems' was presented for the graduation: 'Habilitation a diriger des recherches'. The common thread of both themes liquid scintillation counting and pressurized ionization chambers lies in the improvement of the techniques of radionuclide activity measurement. Metrology of ionization radiation intervenes in numerous domains, in the research, in the industry including the environment and the health, which are subjects of constant concern for the world population these last years. In this big variety of applications answers a large number of radionuclides of diverse disintegration scheme and under varied physical forms. The presented works realized within the National Laboratory Henri Becquerel have for objective to assure detector calibration traceability and to improve the methods of activity measurements within the framework of research projects and development. The improvement of the primary and secondary activity measurement methods consists in perfecting the accuracy of the measurements in particular by a better knowledge of the parameters influencing the detector yield. The works of development dealing with liquid scintillation counting concern mainly the study of the response of liquid scintillators to low energy electrons as well as their linear absorption coefficients using synchrotron radiation. The research works on pressurized ionization chambers consist of the study of their response to photons and electrons by experimental measurements compared to the simulation of the source-detector system using Monte Carlo codes. Besides, the design of a new type of ionization chamber with variable pressure is presented. This new project was developed to guarantee the precision of the amount of activity injected into the patient within the framework of diagnosis examination

Alpha/beta separation in liquid scintillation gel samples

International Nuclear Information System (INIS)

Grau Carles, A.; Grau Malonda, A.

1994-01-01

The pulse shape analysis commonly used in liquid scintillation alpha/beta separations is satisfactory for moderate quench levels. However, for gel samples, the alpha particle counting efficiency is never greater than 10%, and an optimum separation of the alpha component cannot be achieved when beta to alpha counting rate ratios are greater than 100. In such cases, it is better to use a spectrum analysis method for alpha/beta separation. ((orig.))

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

International Nuclear Information System (INIS)

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

1987-01-01

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 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

Determination of 226Ra and 224Ra in sediments samples by liquid scintillation counting

International Nuclear Information System (INIS)

Villa, M.; Moreno, H.P.; Manjon, G.

2005-01-01

An experimental procedure has been developed for a rapid determination of the activity concentration of 226 Ra and 224 Ra in sediments by liquid scintillation counting. The importance of the method lies in its application to the measurement of sediments where the Ra-isotopes activity concentration has been increased due to an anthropomorphic enhancement based on releases of naturally occurring radioactive material (NORM). A sample pre-treatment, including a digestion with aqua regia and a precipitation of hydroxides, was applied to samples before the radium extraction, which was made by co-precipitation with barium. Measurements were done in a low background scintillation spectrometer Quantulus 1220, which can separate and detect simultaneously α and β particles. Additionally, some improvements are suggested for a better α and β interference correction of the results. The obtaining of radiochemical yields is also improved using 133 Ba as tracer, which decays by emission of conversion electrons and γ-rays; the wide range of radiochemical yields obtained confirms the need of this analyses. The procedure has been applied to the measurement of riverbed sediments from an estuary in the south-west of Spain, affected in the past by direct and indirect phosphogypsum discharges

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

Energy Technology Data Exchange (ETDEWEB)

Appriou, D.; Doury, A.

1962-07-01

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

A Performance Comparison of Nine Selected Liquid Scintillation Cocktails

Energy Technology Data Exchange (ETDEWEB)

Verrezen, F; Loots, H; Hurtgen, Ch

2008-06-15

In the selection of a suitable liquid scintillation (LSC) cocktail, the primary aspects taken into consideration are overall cocktail performance and specific laboratory needs. Overall performance of 9 selected, commercially available LSC cocktails was assessed by studying parameters of importance for the requirements of the Laboratory for Low Level Radioactivity Measurements of SCK-CEN: sample load capacity, sample compatibility, influence of sample load on counting efficiency, background count rate, figure of merit, quench resistance, sample stability and alpha/beta separation characteristics. The cocktails tested were EcoscintA, Insta Gel Plus, OptiPhase Hisafe3, OptiPhase Trisafe, Ready Gel, SafeScint 1:1, Ultima Gold, Ultima Gold LLT, and Ultima Gold XR. For the data acquisition a Packard TriCarb Model 1900CA and a Quantulus 1220 liquid scintillation counter is used. All samples were prepared in either 20 mL low potassium, borosilicate glass vials or 20 mL high density, polyethylene vials. The aim of this study was to determine a single cocktail that best suits all measurement requirements of the liquid scintillation laboratory at SCK-CEN for the determination of low levels of radioactivity in biological and environmental samples. As a conclusion, Optiphase HiSafe 3 was confirmed to be the optimal cocktail for the laboratory.

A Performance Comparison of Nine Selected Liquid Scintillation Cocktails

International Nuclear Information System (INIS)

Verrezen, F.; Loots, H.; Hurtgen, Ch.

2008-01-01

In the selection of a suitable liquid scintillation (LSC) cocktail, the primary aspects taken into consideration are overall cocktail performance and specific laboratory needs. Overall performance of 9 selected, commercially available LSC cocktails was assessed by studying parameters of importance for the requirements of the Laboratory for Low Level Radioactivity Measurements of SCK-CEN: sample load capacity, sample compatibility, influence of sample load on counting efficiency, background count rate, figure of merit, quench resistance, sample stability and alpha/beta separation characteristics. The cocktails tested were EcoscintA, Insta Gel Plus, OptiPhase Hisafe3, OptiPhase Trisafe, Ready Gel, SafeScint 1:1, Ultima Gold, Ultima Gold LLT, and Ultima Gold XR. For the data acquisition a Packard TriCarb Model 1900CA and a Quantulus 1220 liquid scintillation counter is used. All samples were prepared in either 20 mL low potassium, borosilicate glass vials or 20 mL high density, polyethylene vials. The aim of this study was to determine a single cocktail that best suits all measurement requirements of the liquid scintillation laboratory at SCK-CEN for the determination of low levels of radioactivity in biological and environmental samples. As a conclusion, Optiphase HiSafe 3 was confirmed to be the optimal cocktail for the laboratory.

Problems associated with scintillation counting of NaH14CO3 and gel suspension counting of Ba14CO3

International Nuclear Information System (INIS)

MacRae, J.C.; Wilson, S.

1978-01-01

Liquid NaH 14 CO 3 was assayed in emulsion-type (NE260 and Unisolve) and dioxan-based (NE250) scintillation cocktails contained in glass or polyethylene vials kept at 2 0 or 24-30 0 C. Different particle size ranges of standard Ba 14 CO 3 were assayed by gel suspension counting in Cabosil scintillation cocktail and in NE260 following solubilisation in EDTA-tetrasodium salt. Initial detectable activities of NaH 14 CO 3 in glass and polyethylene vials in NE250, NE260 and Unisolve were 97 and 96, 68 and 83, 71 and 89% of the true value respectively. Subsequent losses of activity over 7 days with the emulsion-type scintillators was greater from the polyethylene vials. Addition of phenylethylamine to the NE260 and Unisolve cocktails gave the true activity levels for all vials with no loss of activity over 6 days. When different particle size ranges of Standard Ba 14 CO 3 were suspended in Cabosil scintillation cocktail there was considerable variation in counting efficiency (77-88%) with little relationship between particle size and counting efficiency. The relationship between counting efficiency and channels ratio was not sufficiently precise for predictive purposes. Solubilisation of Ba 14 CO 3 in EDTA-tetrasodium salt gave similar counting efficiency and channels ratio values for all samples. (U.K.)

Liquid scintillation solution

International Nuclear Information System (INIS)

Long, E.C.

1977-01-01

A liquid scintillation solution is described which includes (1) a scintillation solvent (toluene and xylene), (2) a primary scintillation solute (PPO and Butyl PBD), (3) a secondary scintillation solute (POPOP and Dimethyl POPOP), (4) a plurality of substantially different surfactants and (5) a filter dissolving and/or transparentizing agent. 8 claims

QUENCH: A software package for the determination of quenching curves in Liquid Scintillation counting.

Science.gov (United States)

Cassette, Philippe

2016-03-01

In Liquid Scintillation Counting (LSC), the scintillating source is part of the measurement system and its detection efficiency varies with the scintillator used, the vial and the volume and the chemistry of the sample. The detection efficiency is generally determined using a quenching curve, describing, for a specific radionuclide, the relationship between a quenching index given by the counter and the detection efficiency. A quenched set of LS standard sources are prepared by adding a quenching agent and the quenching index and detection efficiency are determined for each source. Then a simple formula is fitted to the experimental points to define the quenching curve function. The paper describes a software package specifically devoted to the determination of quenching curves with uncertainties. The experimental measurements are described by their quenching index and detection efficiency with uncertainties on both quantities. Random Gaussian fluctuations of these experimental measurements are sampled and a polynomial or logarithmic function is fitted on each fluctuation by χ(2) minimization. This Monte Carlo procedure is repeated many times and eventually the arithmetic mean and the experimental standard deviation of each parameter are calculated, together with the covariances between these parameters. Using these parameters, the detection efficiency, corresponding to an arbitrary quenching index within the measured range, can be calculated. The associated uncertainty is calculated with the law of propagation of variances, including the covariance terms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of triple to double coincidence ratio and Quench Parameter External methods for the determination of 3H efficiency by liquid scintillation counting

International Nuclear Information System (INIS)

Nisti, M.B.; Saueia, C.H.R.; Mazzilli, B.P.

2013-01-01

The aim of this study is to determine the tritium efficiency by liquid scintillation counting using two methodologies, Quench Parameter External (QPE) and Triple to Double Coincidence Ratio (TDCR), and to compare the results. The equipment used was the HIDEX model 300-SL Liquid Scintillation Counter, composed of three photomultipliers coupled with coincidence pulses, discrimination level and Mikro Win 2000 software. The efficiency varied from 0.028 to 0.706 cps dps -1 for QPE and from 0.061 to 0.703 cps dps -1 for TDCR. Different efficiencies were obtained using both methods, in the range from 459 to 572 quenching, above this range the efficiencies were similar. The verification of the efficiencies was performed by participating in the Intercomparison National Program (PNI). (author)

Gross alpha and gross beta determination in surface and groundwater water by liquid scintillation counting (LSC)

International Nuclear Information System (INIS)

Faria, Ligia S.; Moreira, Rubens M.

2013-01-01

The present study has used 40 samples of groundwater and surface water collected at four different sites along the period of one year in Brumadinho and Nova Lima, two municipalities in the State of Minas Gerais, Brazil, as part of a more extensive study aiming at determination of the natural radioactivity in the water used for domestic use. These two sites are inside an Environmental Protection Area is located in a region of very intensive iron ore exploration. In addition of mineral resources, the region has a geological characteristic that includes quartzitic conglomerates associated with uranium. Radioactivity levels were determined via liquid scintillation counting (LSC), a fast and high counting efficiency method that can be advantageously employed to determine gross alpha and gross beta activity in liquid samples. Previously to gross alpha and gross beta counting the samples were acidified with concentrated HNO 3 in the field. The technique involved a pre-concentration of the sample to obtain a low detection limit. Specific details of the employed methodology are commented. The results showed that concentrations of gross alpha natural activity and gross beta values ranged from less than the detection limit of the equipment (0.03 Bq.L -1 ) to 0.275 ± 0.05 Bq.L -1 for gross alpha. As regards gross beta, all samples were below the limit of detection. (author)

Determination of 63Ni and 55Fe in nuclear waste samples using radiochemical separation and liquid scintillation counting

DEFF Research Database (Denmark)

Hou, Xiaolin; Frøsig Østergaard, L.; Nielsen, S.P.

2005-01-01

An analytical method for the determination of Ni-63 and Fe-55 in nuclear waste samples such as graphite, heavy concrete, aluminium and lead was developed. Different decomposition methods (i.e. ashing, acid digestion and alkali fusion) were investigated for the decomposition of the samples...... by extraction chromatography. The purified Ni-63 and Fe-55 was then measured by liquid scintillation counting. The chemical yields of the separation procedures for Fe-55 and Ni-63 are above 90% and the decontamination factors for all interfering radionuclides are more than 10(5). The detection limits...

Chemical and colour quenching in liquid scintillation counting; Estudio de la extincion quimica y por color en centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Scott, P E; Grau, A

1987-07-01

Chemical and colour quenching for H-3 and C-14 was studied. The method includes spectral analysis of colouring agents; methyl red, (4'-dimethylamine-azobenzene 2-carboxylic acid) dimethyl yellow (4'-dimethylamine-azobenzene) and malachite green (methane, bis .(4-dimethyl aminophenyl) - (phenyl)). External standard channels ratio was applied for the liquid scintillation counting of samples. The introduction of an isolated external standard seems to be a strong tool for the correction of chemical and colour quenching curves. (Author) 12 refs.

Chemical and colour quenching in liquid scintillation counting; Estudio de la extincion quimica y por color en centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Scott, P. E.; Grau, A.

1987-07-01

Chemical and colour quenching for H-3 and C-14 was studied. The method includes spectral analysis of colouring agents; methyl red, (4'-dimethylamine-azobenzene 2-carboxylic acid) dimethyl yellow (4'-dimethylamine-azobenzene) and malachite green (methane, bis .(4-dimethyl aminophenyl) - (phenyl)). External standard channels ratio was applied for the liquid scintillation counting of samples. The introduction of an isolated external standard seems to be a strong tool for the correction of chemical and colour quenching curves. (Author) 12 refs.

Selective solvent extraction of actinides associated to liquid scintillation measurements

International Nuclear Information System (INIS)

Ardois, C.; Musikas, C.

1997-01-01

The problems associated to radioactive waste disposal have acquired a special attention due, particularly, to the element instability and, consequently, to their lixiviation and to their peculiarities which are essential in the radioactivity penetration in the food chains; the other important parameters are the produced amounts and the noxiousnesses. New commercial liquid scintillation counters allow rapid α/β measurements. Associated with liquid-liquid extraction techniques, rapid and selective actinide analyses are possible. Among various actinide extractants, such as amines or organophosphorus compounds, we were particularly interested in tri-n-octyl-phosphine oxide (TOPO). Uranium, thorium and americium extractions with (TOPO) in toluene have been investigated. A systematic study of the counting parameters of a PACKARD 2550 TR/AB TM liquid scintillation analyzer is under completion

Liquid scintillation solution

International Nuclear Information System (INIS)

Long, E.C.

1976-01-01

The invention deals with a liquid scintillation solution which contains 1) a scintillation solvent (toluol), 2) a primary scintillation solute (PPO), 3) a secondary scintillation solute (dimethyl POPOP), 4) several surfactants (iso-octyl-phenol polyethoxy-ethanol and sodium di-hexyl sulfosuccinate) essentially different from one another and 5) a filter resolution and/or transparent-making agent (cyclic ether, especially tetrahydrofuran). (HP) [de

Rapid bioassay method for estimation of 90Sr in urine samples by liquid scintillation counting

International Nuclear Information System (INIS)

Wankhede, Sonal; Chaudhary, Seema; Sawant, Pramilla D.

2018-01-01

Radiostrontium (Sr) is a by-product of the nuclear fission of uranium and plutonium in nuclear reactors and is an important radionuclide in spent nuclear fuel and radioactive waste. Rapid bioassay methods are required for estimating Sr in urine following internal contamination. Decision regarding medical intervention, if any can be based upon the results of urinalysis. The present method used at Bioassay Laboratory, Trombay is by Solid Extraction Chromatography (SEC) technique. The Sr separated from urine sample is precipitated as SrCO 3 and analyzed gravimetrically. However, gravimetric procedure is time consuming and therefore, in the present study, feasibility of Liquid Scintillation Counting for direct detection of radiostrontium in effluent was explored. The results obtained in the present study were compared with those obtained using gravimetric method

On the use of liquid scintillation counting of 51Cr and 14C in the twin tracer method of measuring assimilation efficiency

International Nuclear Information System (INIS)

Cammen, L.M.

1977-01-01

Calow and Fletcher (1972) calculated assimilation efficiency from the ratio of an assimilated radiotracer ( 14 C) to a non-assimilated tracer ( 51 Cr) in food and feces. Wightman (1975) improved the efficiency of their technique by using liquid scintillation to count both isotopes simultaneously, but stated incorrectly that it was not necessary to convert count per minute (CPM) to disintegration per minute (DPM). Unless the CPM data are corrected for quenching and converted to DPM prior to calculation of assimilation efficiency, a significant error may be introduced. (orig.) [de

An improved method for 85Kr analysis by liquid scintillation counting and its application to atmospheric 85Kr determination

International Nuclear Information System (INIS)

Momoshima, Noriyuki; Inoue, Fumio; Sugihara, Shinji; Shimada, Jun; Taniguchi, Makoto

2010-01-01

Atmospheric 85 Kr concentration at Fukuoka, Japan was determined by an improved 85 Kr analytical method using liquid scintillation counting (LSC). An average value of 1.54 ± 0.05 Bq m -3 was observed in 2008, which is about two times that measured in 1981 at Fukuoka, indicating a 29 mBq y -1 rate of increase as an average for these 27 years. The analytical method developed involves collecting Kr from air using activated charcoal at liquid N 2 temperature and purifying it using He at dry ice temperature, followed by Kr separation by gas chromatography. An overall Kr recovery of 76.4 ± 8.1% was achieved when Kr was analyzed in 500-1000 l of air. The Kr isolated by gas chromatography was collected on silica gel in a quartz glass vial cooled to liquid N 2 temperature and the activity of 85 Kr was measured with a low-background LS counter. The detection limit of 85 Kr activity by the present analytical method is 0.0015 Bq at a 95% confidence level, including all propagation errors, which is equivalent with 85 Kr in 1.3 l of the present air under the analytical conditions of 72.1% counting efficiency, 0.1597 cps background count rate, and 76.4% Kr recovery.

Usage of liquid scintillation counting for detecting the chemiluminescence of cells and its application in medicine

International Nuclear Information System (INIS)

Li Tianxing; Liang Qizhong; Zou Xiaowei; Yang Zhaohen; Huang Yong; Li Huaqiang

1995-01-01

The liquid scintillator counting-chemiluminescence (LSC-CL) of mono-photon radiance is a sensitive, handy and high-autoanalytic technique. Through measuring basic CL, dependent CL and maximum phagocytic CL of polymorphonuclear (PMN), we studied best factor levels of the method with orthogonal design [L 9 (3 4 )]. The results showed the peak forms changed markedly (inter-group P -4 M). PMN-CL in blood was measured during acute attack of the old patients with chronic bronchitis and the children with pneumonia bronchial. It was suggested that PMN phagocytosis decreased. So the dynamic analysis of maximum phagocytic CL would help us with the deep going clinical researches of the mechanisms of anti-inflammation and injuring by the oxygen free radicals

Applications of commercial liquid scintillation counters to radon-222 and radium-226 analyses

International Nuclear Information System (INIS)

Gesell, T.F.; Prichard, H.M.; Haygood, J.R.

1978-01-01

The ubiquitous commerical liquid scintillation counter offers automatic sample processing, automatic data recording and the prospect of multiple users. With these features in mind we have explored a number of applications of liquid scintillation counters to environmental and health physics problems. One application, the analysis of radon in water has been described elsewhere and is only briefly reviewed. A method for measuring radon in air, two methods for measuring radium in water, and a technique for leak testing radium needles have also been investigated. An ordinary glass scintillation vial is readily converted into a miniature scintillation flask by coating the inside surface with a thin layer in ZnS:Ag phosphor. The lower limit detection is high, about 2 pCi/1 for a 1 hour count, but these flasks have proved to be useful in situations where a larger number of samples must be taken in environments with relatively high levels of radon. One technique for the detection of radium in water uses liquid-liquid extraction to concentrate radon into an organic scintillation fluid, the other involves passing the water sample through an ion exchange resin and then sealing the resin and scintillation fluid in a vial. Both techniques offer the prospect of easy and inexpensive analyses with limits of detection at or below 0.5 pCi/1. Radium needles can be leak tested by placing them in vials containing toluene for a few minutes, adding fluor to the toluene and counting. Preliminary data regarding these several methods are given

The measurement of 222Rn in drinking water by low-level liquid scintillation counting

International Nuclear Information System (INIS)

Barnett, J.M.; McKlveen, J.W.

1992-01-01

Radon-222 (Rn) has universally been found in well water. Non-stagnant ground water is collected at the well head while the well is pumping. The water is adjusted to a slow, non-aerated, steady flow through a clear tube, and a 500 ml glass bottle is filled. The sample is tightly capped after a high meniscus has developed. In the laboratory, standard 22 ml glass vials are filled with 10 ml of a toluene based mineral oil LS cocktail. Then, two 5 ml sample aliquots are pipetted into the vial. Vials are capped tightly, shaken vigorously, and placed in the liquid scintillation (LS) counter. Secular equilibrium is established in approximately 4 hours, after which samples are counted for 100 minutes each. The counting efficiency for Rn and progeny ranges between 315 to 345 percent depending on the chosen spectral window. The average background is about 6 cpm. A total of 28 wells were tested for Rn in the Carefree-Cave Creek, Arizone, USA area. The area's geometric average Rn concentration was found to be 46.5 Bq*1 -1 . The associated estimated lung dose is 0.51 mSv*y -1 . (author) 8 refs.; 1 fig.; 1 tab

Neutron crosstalk between liquid scintillators

Energy Technology Data Exchange (ETDEWEB)

Verbeke, J.M., E-mail: verbeke2@llnl.gov; Prasad, M.K., E-mail: prasad1@llnl.gov; Snyderman, N.J., E-mail: snyderman1@llnl.gov

2015-09-11

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.

Neutron crosstalk between liquid scintillators

International Nuclear Information System (INIS)

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

2015-01-01

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

Liquid scintillator mixable with water

International Nuclear Information System (INIS)

Benson, R.H.

1976-01-01

A liquid scintillator mixable with water is described consisting of an aromatic solvent (xylene), a scintillation material and an ethoxylated alkyl phenol (as surface-active substance). So far such kinds of system have not given good measurements on counting samples with high water content. Due to the invention's composition one gets good results even with counting samples having a water content of over 30% if the alkyl substituent of the alkyl phenol contains 7, 10, 11, 13, 14, 15 or 16 C atoms and the ratio n/x of the number n of C atoms of the alkyl substituents to the average number x of the ethoxy groups of the ethoxylated alkyl phenols lie between 0.83 and 1.67. The following alkyl phenols are mentioned: heptyl phenol (n/x between 0.83 and 1.08), decyl phenol (n/x between 0.90 and 1.17), hendecyl phenol (n/x between 0.93 and 1.22), tridecyl phenol (n/x between 0.97 and 1.34), tetradecyl phenol (n/x between 1.08 and 1.55), pentadecyl phenol (n/x between 1.15 and 1.67), hexadecyl phenol (n/x between 1.33 and 1.51). (UWI) [de

The liquid scintillation counting efficiency for 137mCs+137mBa and ''129 I; 'Eficiencias de recuento por centelleo liquido para el Cs+13 mBa y ''129 I

Energy Technology Data Exchange (ETDEWEB)

Grau CarLes, A.; Grau Malonda, A.

1995-07-01

We compute the liquid scintillation counting efficiency for 137Cs+137mBa and ''129 I taking into account the scintillator chemical composition. We consider the beta transition shape factors for the for bidden beta transitions of these nuclides, and the effects of 137mBa and 129mXe half-lives on the total counting efficiency. (Author) 8 refs.

14C measurement: effect of variations in sample preparation and storage on the counting efficiency for 14C using a carbo-sorb/permafluor E+ liquid scintillation cocktail

International Nuclear Information System (INIS)

Kramer, S.J.; Milton, G.M.; Repta, C.J.W.

1995-06-01

The effect of variations in sample preparation and storage on the counting efficiency for 14 C using a Carbo-Sorb/PermafluorE+ liquid scintillation cocktail has been studied, and optimum conditions are recommended. (author). 2 refs., 2 tabs., 4 figs

Detectors for proton counting. Si-APD and scintillation detectors

International Nuclear Information System (INIS)

Kishimoto, Shunji

2008-01-01

Increased intensity of synchrotron radiation requests users to prepare photon pulse detectors having higher counting rates. As detectors for photon counting, silicon-avalanche photodiode (Si-APD) and scintillation detectors were chosen for the fifth series of detectors. Principle of photon detection by pulse and need of amplification function of the detector were described. Structure and working principle, high counting rate measurement system, bunch of electrons vs. counting rate, application example of NMR time spectroscopy measurement and comments for users were described for the Si-APD detector. Structure of scintillator and photomultiplier tube, characteristics of scintillator and performance of detector were shown for the NaI detector. Future development of photon pulse detectors was discussed. (T. Tanaka)

Method for determining efficiency in a liquid scintillation system

International Nuclear Information System (INIS)

Laney, B.H.

1975-01-01

In a liquid scintillation system utilizing plural photomultiplyier means, a method for determining efficiency of coincident pulse detection. Various incremental counting efficiency levels are associated with asymptotic functions in a two dimension matrix in which the abscissa and ordinate correspond to the pulse heights of each of a pair of coincident pulses from different photomultiplier means. An efficiency determining point is located in the matrix based on the sum of the pulse heights of each of the coincident pulses as well as on the amplitude of the smallest pulse of the coincident pulses. The single counting efficiency determining point is recorded as the level of efficiency at which the photomultiplier means detect scintillations that generate coincident pulses having pulse heights equal to those recorded. (Patent Office Record)

A scheme for recycling of used liquid scintillation counting cocktail for tritium analysis

International Nuclear Information System (INIS)

Gocher, A.K.; Tailor, S.P.; Tiwari, S.N.; Ravi, P.M.; Tripathi, R.M.

2018-01-01

Ultima Gold LLT TM is a ready to use scintillation cocktail used for estimation of tritium activity in various water sample collected from Rawatbhata Rajasthan Site environment up to 30 km radial distance. The present study explores the possibility of re-using the cocktail used in non detect (BDL) samples for counting of high active samples. Results of tritium standard counted with used cocktail (UC) was within ±10 % variation w.r.t fresh Ultima gold scintillation cocktail. Also results of high active samples prepared using 20 ml Used Cocktail (UC) and 1 ml sample (20 ml UC: 1ml aq. sample) were found in the range -7% to +11.1% w.r.t same sample prepared using fresh Ultima Gold. Used cocktail (UC) can be reused for tritium activity estimation of high active samples. Re-using of used cocktail will ultimately reduce the cocktail consumption, reduce the operational cost and reduce the quantity of waste cocktail disposal to the environment

A comparative study using liquid scintillation counting to determine 63Ni in low and intermediate level radioactive waste

International Nuclear Information System (INIS)

Gautier, Celine; Colin, Christele; Garcia, Cecile

2016-01-01

A comparative study using liquid scintillation counting was performed to measure 63 Ni in low and intermediate level radioactive waste. Three dimethylglyoxime (DMG)-based radiochemical procedures (solvent extraction, precipitation, extraction chromatography) were investigated, the solvent extraction method being considered as the reference method. Theoretical speciation calculations enabled to better understand the chemical reactions involved in the three protocols and to optimize them. In comparison to the method based on DMG precipitation, the method based on extraction chromatography allowed to achieve the best results in one single step in term of recovery yield and accuracy for various samples. (author)

Liquid scintillation spectrometer survey 155Eu liquid activity

International Nuclear Information System (INIS)

Zhang Zuhua

2002-01-01

In the countrywide contrasting survey of 155 Eu activity, 155 Eu liquid activity was determined for the first time through using liquid scintillation spectrometer survey 155 Eu β ray. In survey total uncertainty, determining activity accord with determining activity average value of all a wide variety of survey instrument entering into contrasting survey. But using liquid scintillation spectrometer survey, it is simple and save time, is beyond compare for other survey method. It indicate liquid scintillation spectrometer survey β-γ nuclide activity is effective as well

Nanophosphor composite scintillator with a liquid matrix

Science.gov (United States)

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.

The measurement of Rn-222 in drinking water by low-level liquid scintillation counting

International Nuclear Information System (INIS)

Barnett, J.M.; McKlveen, J.W.

1991-01-01

Radon-222 has consistently been found in well water. The research objectives are to establish a method to collect well water and to measure the Rn in ground water using liquid scintillation (LS) counting. Water is collected at the well head while the well is pumping. The water is adjusted to a slow, non-aerated, steady flow through a clear tube, and a 437 mL (16 oz) glass bottle is filled. The sample is tightly capped after a high meniscus has developed. In the laboratory, standard 22 mL LS glass vials are filled with 10 mL of a toluene based mineral oil LS cocktail. Then, two 5 mL sample aliquots are pipetted into the vial. Vials are capped tightly, shaken vigorously, and placed in the LS counter. Secular equilibrium is established in approximately 3.5 hours, after which samples are counted for 100 minutes each. Quality assurance and control is performed weekly on the LS counter's electronics, spectral window, counting efficiency, and background. The counting efficiency ranges between 315-345 percent depending on the chosen spectral window. The average background is about 6 cpm. A total of 28 wells were tested for Rn in the Carefree-Cave Creek, Arizona, USA area, and 12 wells were selected, each over 50 Bq/L (1,350 pCi/L), for an extended 6 month period. The area's average Rn concentration was found to be 46.5 Bq/L (1,255 pCi/L); it is a geometric mean. The associated estimated lung dose is 1.13 mSv/a

Study of the peak shape in alpha spectra measured by liquid scintillation

CERN Document Server

Vera-Tome, F; Martin-Sanchez, A

2002-01-01

Liquid-scintillation counting allows the measurement of alpha and beta activities jointly or only of the alpha-emitting nuclides in a sample. Although the resolution of the alpha spectra is poorer than that attained with semiconductor detectors, it is still an attractive alternative. We describe here attempts to fit a peak shape to experimental liquid-scintillation alpha spectra and discuss the parameters affecting this shape, such as the PSA (pulse-shape analyser) level, vial type, shaking the sample, etc. Spectral analysis has been applied for complex alpha spectra.

Determination of 131I in milk using a liquid scintillation technique

International Nuclear Information System (INIS)

Palagyi, S.; Markusova, R.

1978-01-01

The method is based on the specific extraction of radioiodine using a liquid anion exchanger and measuring its radioactivity with a toluene based liquid scintillator. Milk proteins are precipitated with trichloroacetic acid and separated by filtration through asbestos. Radioiodine from whey is oxidized to I 2 with NaNO 2 or H 2 O 2 and purified by a benzene-water extraction cycle using sodium sulphite. Finally, the radioiodine is separated and concentrated into toluene solution of a liquid anion exchanger. Before radioactivity counting, the organic phase is decolourized with Na 2 SO 3 using methanol as solubilizer. The method takes about 2.5 hrs without radioactivity counting. The radiochemical yield is higher than 70% and the counting efficiency is 82%. (author)

Preparation and calibration by liquid scintillation of a sample of Cl 36

International Nuclear Information System (INIS)

Grau Malonda, A.; Los Arcos, J.M.; Rodriguez Barquero, L.; Suarez, C.

1989-01-01

A procedure to prepare a sample of Clorine 36, as Li 36 Cl, able to be measured by liquid scintillation counting, is described. The sample is chemically stable, with no variation of the quenching parameter up to 4 mg of LiCl per 15 ml of scintillator, keeps constant the counting efficiency for concentration higher than 40 μg of Li 36 Cl in that volume, and shows no deterioration over a 3 weed period. The Li 36 Cl solution has been standarized using the free parameter method with different volumes of toluene, PCS and Instagel, to an uncertainty of 0,3% (Author)

The determination of 14CO2 in breath by liquid scintillation counting

International Nuclear Information System (INIS)

Ozker, K.; East, B.W.; Boddy, K.

1977-03-01

A sensitive method of sampling and measuring the specific activity of 14 CO 2 in expired breath in order to evaluate the metabolic pathways of 14 C-labelled compounds has been devised. 14 CO 2 is blown through a short plastic tube, attached to a drier, into a scintillation vial containing hyamine hydroxide and ethanol. 14 CO 2 was generated to the end-point of neutralization of hyamine hydroxide, indicated by the decolourisation of phenolphthalein. 14 CO 2 was counted after mixing the hyamine hydroxide and ethanol with 15ml toluene scintillation solution. The specific activity of 14 CO 2 from the samples was compared with that of solutions of known activity. The method is sensitive for clinical applications and can be performed at a patient's bedside. (U.K.)

Water quality - Determination of tritium activity concentration - Liquid scintillation counting method (International Standard Publication ISO 9698:1989)

International Nuclear Information System (INIS)

Stefanik, J.

1999-01-01

This International Standard specifies a method for the determination of tritiated water ([ 3 H]H 2 O) activity concentration in water by liquid scintillation counting. The method is applicable to all types of water including seawater with tritium activity concentrations of up to 10 6 Bq/m 3 when using 20 ml counting vials. Below tritium activity concentrations of about 5 x 10 4 Bq/m 3[ 8], a prior enrichment step and/or the measurement of larger sample volumes can significantly improve the accuracy of the determination and lower the limit of detection. Tritium activity concentrations higher than 10 6 Bq/m 3 may be determined after appropriate dilution with distilled water of proven low tritium content. An alternative method for the determination of these higher activities involves increasing the tritium activity concentrations of the internal standard solution. The method is not applicable to the analysis of organically bound tritium; its determination requires an oxidative digestion

QUENCH: A software package for the determination of quenching curves in Liquid Scintillation counting

International Nuclear Information System (INIS)

Cassette, Philippe

2016-01-01

In Liquid Scintillation Counting (LSC), the scintillating source is part of the measurement system and its detection efficiency varies with the scintillator used, the vial and the volume and the chemistry of the sample. The detection efficiency is generally determined using a quenching curve, describing, for a specific radionuclide, the relationship between a quenching index given by the counter and the detection efficiency. A quenched set of LS standard sources are prepared by adding a quenching agent and the quenching index and detection efficiency are determined for each source. Then a simple formula is fitted to the experimental points to define the quenching curve function. The paper describes a software package specifically devoted to the determination of quenching curves with uncertainties. The experimental measurements are described by their quenching index and detection efficiency with uncertainties on both quantities. Random Gaussian fluctuations of these experimental measurements are sampled and a polynomial or logarithmic function is fitted on each fluctuation by χ"2 minimization. This Monte Carlo procedure is repeated many times and eventually the arithmetic mean and the experimental standard deviation of each parameter are calculated, together with the covariances between these parameters. Using these parameters, the detection efficiency, corresponding to an arbitrary quenching index within the measured range, can be calculated. The associated uncertainty is calculated with the law of propagation of variances, including the covariance terms. - Highlights: • The program “QUENCH” is devoted to the interpolation of quenching curves in LSC. • Functions are fitted to experimental data with uncertainties in both quenching and efficiency. • The parameters of the fitting function and the associated covariance matrix are evaluated. • The detection efficiency and uncertainty corresponding to a given quenching index is calculated.

Liquid Scintillation High Resolution Spectral Analysis

Energy Technology Data Exchange (ETDEWEB)

Grau Carles, A.; Grau Malonda, A.

2010-08-06

The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

Liquid Scintillation High Resolution Spectral Analysis

International Nuclear Information System (INIS)

Grau Carles, A.; Grau Malonda, A.

2010-01-01

The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

A comparison between the measurements of Kr-85 in environmental samples by liquid scintillation and proportional counters

International Nuclear Information System (INIS)

Heras Iniquez, M.C.; Perez Garcia, M.M.

1983-01-01

The most used methods for the measurement of Kr-81 beta-activity after their concentration and aisolation are the liquid scintillation counting and the proportional counter. In this work the beta activity of concentrated and aisolated Kr-85 samples measured in collaboration with the Max-Planck Institut fur Kernphyslk, Aussenstelle Freiburg. Samples taken both In Madrid and Frelburg are measured by proportional counters in the Max-Planck lnstitut, Freibury and by liquid scintillation counting in JEN, Madrid. The comparison of both measurements do not show appreciable discrepancy between the results obtained to both techniques. (Author)

Performance of two liquids scintillation and optimization of a Wallac 1411 counter in the tritium quantification in aqueous samples

International Nuclear Information System (INIS)

Contreras de la Cruz, E. de J.; Lopez del Rio, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L.

2014-10-01

The optimization of a liquid scintillation counting Wallac 1411 is presented as well as the performance of the liquids scintillation miscible in water OptiPhase Hi Safe 3 and Last Gold Ab, in the tritium quantification in aqueous samples. The luminescence effect, the quenching, the solution ph and the level of pulse amplitude comparator (Pac) were evaluated in the response of both liquids scintillation in the tritium measurement. The quenching and the luminescence modify the scintillators response; in the first of them the counting efficiency decreases and the minimum detectable activity increases; the second interferes in the tritium quantification in the interest window, but the effect disappears after 4 hours of darkness of the samples. The maximum counting efficiency was of 24% for OptiPhase Hi Safe 3 and 31% for Last Gold Ab, diminishing with the quenching until values of 8 and 11%, respectively. For a counting time of 6 hours and lower quenching, the minimum detectable concentration for OptiPhase Hi Safe 3 was of 13.4 ± 0.2 Bq/L and 9.9 ± 0.1 Bq/L for Last Gold Ab. Both scintillators responded appropriately to sour and basic solutions, being only presented chemiluminescence in Last Gold Ab to ph highly basic. The Pac application that varies between 1 and 256 does not have effect in the tritium measurement until values above 90. (Author)

Studying, Determining The Radionuclide Of Tritum In The Water Samples (Rain, Surface Water) By Using Liquid Scintillation Counting (TRi-carb 3180TR/SL)

International Nuclear Information System (INIS)

Nguyen Thi Linh; Nguyen Dinh Tung; Truong Y; Le Nhu Sieu; Nguyen Van Phuc; Nguyen Van Phu; Nguyen Kim Thanh

2014-01-01

Tritium in the environment is of natural or man-made origin. Tritium is a radioactive isotope that occurs in the environment and is associated with the interaction of cosmic ray in the atmosphere. However, the most significant sources of tritium in the environment results from nuclear weapons testing in the atmosphere carried out during the late 1950s and early 1960s. Today, the most important new sources of tritium in the environments, such as power stations, processing and using of isotopes released the local tritium. The objective of this study is the application of the liquid scintillation technique to tritium analysis in water samples (rain, and surface waters). Following the Eichrom Tritium Column technique, an aliquot of the passed tritium resin sample (10 mL) is mixed with 10 mL of scintillation cocktail (Ultima Gold LLT, Packard) in 20-mL plastic- container vials and the sample activity is determined using a liquid scintillation spectrometer, Tri-carb 3180TR/SL. Counting efficiency is evaluated with internal standards. The tritium concentrations of water samples that were collected from DaLat, Lamdong range between 0 to 36.2 TU. (author)

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

Directory of Open Access Journals (Sweden)

Arnaud Chapon

Full Text Available 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. Keywords: Liquid Scintillation Counting (LSC, PerkinElmer, Tri-Carb, Smear, Swipe

Stability and reproducibility of gel-suspension samples for the liquid scintillation counting of 14C using N-lauroyl-L-glutamic-α,γ-dibutylamide

International Nuclear Information System (INIS)

Wakabayashi, G.; Ohura, H.; Okai, T.; Matoba, M.

1999-01-01

Stability and reproducibility of gel-suspension method for 14 C activity measurement. Commercially available gelling agent, N-lauroyl-L-glutamic-α,γ-dibutylamide, was used for the gel-formation of the samples. No change of the counting rate for the gel-suspension sample was observed for more than 2 years after the sample preparation. Four samples used for checking the reproducibility of the sample preparation method. The same values were obtained for the counting rate of 14 C activity within the counting error. No change of the counting rate was observed for the 're-gelated' sample. These results show that the gel-suspension method is appropriate for the 14 C activity measurement by the liquid scintillation method and is useful for a long-term preservation of the sample for repeated measurement. (author)

Construction and implementation of a liquid scintillation TDCR system

International Nuclear Information System (INIS)

Wu Yongle; Liang Juncheng; Liu Jiacheng; Yang Yuandi; Yuan Daqing

2012-01-01

The triple-to-double coincidence ratio (TDCR) method is an absolute measurement method of radioactivity, and is a popular technique for the standardization of pure beta radionuclides. A triple-to-double coincidence ratio (TDCR) liquid scintillation counting system has been constructed in China. A description of the system and measured activities for sources such as 3 H and 99 Te are presented. (authors)

Test use of 'Ready Cap' for radiation measurement with a liquid scintillation counter

International Nuclear Information System (INIS)

Kato, Takahisa; Saito, Kazumi; Kurihara, Norio

1989-01-01

We tested the performance of 'Ready Cap' which can be used in place of liquid scintillation cocktails to measure the activity of 3 H and 14 C with a liquid scintillation counter, and observed satisfactory results on counting efficiencies for these nuclides. We could correct color-quenching with Ready Cap either by a method of the gravity-center of β-ray spectrum or by an external standard method that uses the external irradiation from bottom of the sample. Although there are several problems such as limitation of the maximum sample volumes (<200 μl) and sample preparation procedures (drying the sample solution), we can conveniently employ Ready Cap in some aspects of activity counting because of the easy disposal procedure of the radioactive waste resulting from it. (author)

Measurement of 226Ra in water and 222Rn in water and air by liquid scintillation counting

International Nuclear Information System (INIS)

Schoenhofer, F.

1992-01-01

In the Austrian province of Lower Austria a comprehensive programme for measurement of 222 Rn and 226 Ra in drinking water was conducted. A simple liquid scintillation counting (LSC) method was used which gives a LLD of 30 mBq per litre for 226 Ra without any chemical separation. Results are presented and the health significance is discussed. For 222 Rn in air a commercially available simple charcoal system with LSC was used. The system was tested in a house with elevated radon concentration under normal living conditions. During relatively short 2-day periods a maximum deviation of ± 30% from the monthly mean value was found. The advantages of LSC are that the procedures are very simple and cheap. (author)

SCINFI, a program to calculate the standardization curve in liquid scintillation counting; SCINFI, un programa para calcular la curva de calibracion eficiencia-extincion en centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Grau Carles, A.; Grau Malonda, A.

1984-07-01

A code, SCINFI, was developed, written in BASIC, to compute the efficiency- quench standardization curve for any radionuclide. The program requires the standardization curve for 3H and the polynomial relations between counting efficiency and figure of merit for both 3H and the problem (e.g. 14{sup C}). The program is applied to the computation of the efficiency-quench standardization curve for 14{sup c}. Five different liquid scintillation spectrometers and two scintillator solutions have bean checked. The computation results are compared with the experimental values obtained with a set of 14{sup c} standardized samples. (Author)

Liquid scintillation measurement. I

International Nuclear Information System (INIS)

Rexa, R.; Tykva, R.

1983-01-01

The individual components of scintillation solutions and their tasks are listed. Explained briefly is the scintillation process in a liquid scintillator. Factors are discussed which influence this process as are methods applied to supress their influence. They include: ionization quenching, quenching by dilution and concentration, chemical, colour, phase and photon quenching and single-photon events causing an undesirable backgorund. (M.D.)

2003: A centennial of spinthariscope and scintillation counting

International Nuclear Information System (INIS)

Kolar, Z.I.; Hollander, W. den

2004-01-01

In 1903 W. Crookes demonstrated in England his 'spinthariscope' for the visual observation of individual scintillations caused by alpha particles impinging upon a ZnS screen. In contrast to the analogue methods of radiation measurements in that time the spinthariscope was a single-particle counter, being the precursor of scintillation counters since. In the same period F. Giesel, J. Elster and H. Geitel in Germany also found that scintillations from ZnS represent single particle events. This paper summarises the historical events relevant to the advent of scintillation counting

Validation the quantification of beta emitters activity in urine by scintillation spectrometry in the liquid phase

International Nuclear Information System (INIS)

Sierra, I.; Hernandez, C.; Benito, P.; Lopez, C.

2013-01-01

In this paper the methodology used in the validation of the technique for quantifying activity of some beta emitters in urine ( 3 H, 1 4C, 3 5S, 3 2P and 9 0Sr) by scintillation spectrometry Liquid Phase (Liquid Scintillation Counting, LSC) is described in bio elimination Laboratory Service CIEMAT Radiation Dosimetry accredited since last year for carrying out assays measure radiation dose based on ISO forth above. (Author)

Characteristics of commercially available well scintillation counting systems

International Nuclear Information System (INIS)

Morris, A.C. Jr.; Dudley, R.A.

1977-01-01

The document contains data on commercially available well scintillation counting systems as collected during early 1977, and up-dated in July 1977, by the staff of the Medical Application Section, Division of Life Sciences, IAEA. These data also appear as Appendix 2 of IAEA-201, Well Scintillation Counting Systems for Nuclear Medicine Applications in Developing Countries, Vienna, 1977. An attempt was made to include instruments currently offered by all manufacturers. However, it is inevitable that several manufacturers remain unknown to the Section, and a number of known manufacturers failed to provide adequate information. (orig.) [de

An improved method for {sup 85}Kr analysis by liquid scintillation counting and its application to atmospheric {sup 85}Kr determination

Energy Technology Data Exchange (ETDEWEB)

Momoshima, Noriyuki, E-mail: momoshima.noriyuki.551@m.kyushu-u.ac.j [Radioisotope Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Inoue, Fumio [Graduate School of Science, Kyushu University, 6-10-1Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Sugihara, Shinji [Radioisotope Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Shimada, Jun [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Taniguchi, Makoto [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan)

2010-08-15

Atmospheric {sup 85}Kr concentration at Fukuoka, Japan was determined by an improved {sup 85}Kr analytical method using liquid scintillation counting (LSC). An average value of 1.54 {+-} 0.05 Bq m{sup -3} was observed in 2008, which is about two times that measured in 1981 at Fukuoka, indicating a 29 mBq y{sup -1} rate of increase as an average for these 27 years. The analytical method developed involves collecting Kr from air using activated charcoal at liquid N{sub 2} temperature and purifying it using He at dry ice temperature, followed by Kr separation by gas chromatography. An overall Kr recovery of 76.4 {+-} 8.1% was achieved when Kr was analyzed in 500-1000 l of air. The Kr isolated by gas chromatography was collected on silica gel in a quartz glass vial cooled to liquid N{sub 2} temperature and the activity of {sup 85}Kr was measured with a low-background LS counter. The detection limit of {sup 85}Kr activity by the present analytical method is 0.0015 Bq at a 95% confidence level, including all propagation errors, which is equivalent with {sup 85}Kr in 1.3 l of the present air under the analytical conditions of 72.1% counting efficiency, 0.1597 cps background count rate, and 76.4% Kr recovery.

Liquid-helium scintillation detection with germanium photodiodes

International Nuclear Information System (INIS)

Luke, P.N.; Haller, E.E.; Steiner, H.M.

1982-05-01

Special high-purity germanium photodiodes have been developed for the direct detection of vacuum ultraviolet scintillations in liquid helium. The photodiodes are immersed in the liquid helium, and scintillations are detected through one of the bare sides of the photodiodes. Test results with scintillation photons produced by 5.3-MeV α particles are presented. The use of these photodiodes as liquid-helium scintillation detectors may offer substantial improvements over the alternate detection method requiring the use of wavelength shifters and photomultiplier tubes

Optimisation of liquid scintillation counting conditions to determine low activity levels of tritium and radiostrontium in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Rauret, Gemma; Mestres, J.S.; Ribera, Merce; Rajadel, Pilar (Barcelona Univ. (Spain). Dept. de Quimica Analitica)

1990-08-01

An optimisation of the counting conditions for the measurement of aqueous solutions of tritium or radiostrontium using Insta-Gel II as scintillator is presented. The variables optimised were the window, the ratio of mass of sample to mass of scintillator and the total volume of the counting mixture. An optimisation function which takes into account each of these variables, the background and also the efficiency is proposed. The conditions established allow the lowest possible detection limit to be reached. For tritium, this value was compared with that obtained when the standard method for water analysis was applied. (author).

Preparation and standardization of a sample of P 32 by liquid scintillation

International Nuclear Information System (INIS)

Rodriguez, L.; Grau, A.; Los Arcos, J.M.; Suarez, C.

1988-01-01

A procedure to standardize P 32 in liquid scintillation counting by labelling a tsributyl phosphate organic molecule is described. This method shows a high counting efficiency, over 99%, while keeping a good stability of samples in PCS or toluene, which vary less that 1% in two weed periods. The global uncertainty that results for calibrating the radioactive solution through this method has been less that 2.2%. (Author)

Time resolution research in liquid scintillating detection

International Nuclear Information System (INIS)

He Hongkun; Shi Haoshan

2006-01-01

The signal processing design method is introduced into liquid scintillating detection system design. By analyzing the signal of liquid scintillating detection, improving time resolution is propitious to upgrade efficiency of detecting. The scheme of realization and satisfactory experiment data is demonstrated. Besides other types of liquid scintillating detection is the same, just using more high speed data signal processing techniques and elements. (authors)

Background characterization in a liquid scintillation spectrometer

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Los Arcos, J.M.; Jimenez de Mingo, A.

1995-01-01

An alternate procedure for background count rate estimation in a liquid scintillation spectrometer is presented, which does not require to measure a blank with similar composition, volume and quench, to the problem sample. The procedure is based on a double linear parameterization which was obtained from a systematic study of the background observed with glass vials, in three different windows, 0 - 20 KeV, 0 - 800 KeV and 0 - 2 MeV, for volume between 2 and 20 mi of three commercial scintillators, Hisafe II, Ultima-Gold and Instagel, and quenching degree in the interval equivalent to 50% - 3% tritium efficiency. This procedure was tested with standard samples of 3H, and led to average discrepancies less than 10% for activity ≥0,6 Bq, against conventional methods for which the discrepancies are twice on average. (Author) 10 refs

Background characterization in a liquid scintillation spectrometer

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Los arcos, J.M.; Jimenez de Mingo, A.

1995-01-01

An alternate procedure for background count rate estimation in a liquid scintillation spectrometer is presented, which does not require to measure a blank with similar composition, volume and quench, to the problem sample. The procedure is based on a double linear parameterization which was obtained from a systematic study of the background observed with glass vials, in three different windows, 0-20 KeV, 0-800 KeV and 0-2 MeV, for volume between 2 and 20 ml of three commercial scintillators, Hisafe II, Ultima-gold and Instagel, and quenching degree in the interval equivalent to 50%-3% tritium efficiency. This procedure was tested with standard samples of ''3 H, and led to average discrepancies less than 10% for activity => 0,6 Bq, against conventional methods for which the discrepancies are twice on average

Liquid scintillation alpha particle spectrometry. Progress report

International Nuclear Information System (INIS)

Bell, L.L.; Hakooz, S.A.; Johnson, L.O.; Nieschmidt, E.B.; Meikrantz, D.H.

1979-12-01

Objective to develop a technique whereby Pu may be put into solution, extracted by solvent extraction into a suitable extractive scintillant and subsequently counted. Presented here are results of attempts to separate beta and alpha activities through pulse shape discrimination. A qualitative discussion is given which yields alpha particle peak widths, resolution and response. The detection efficiency for alpha particles in a liquid scintillant is 100%. Present detection sensitivities of the equipment being used are: 4.5 x 10 -6 μCi (100 s), 1.2 x 10 -6 μCi (1000 s), and 4.0 x 10 -7 μCi (10,000 s) at the 3 sigma level. The detectability of a particular alpha-emitting species is strongly dependent upon the population of other species. The ability to discriminate depends upon the system resolution. 14 figures, 2 tables

Liquid Scintillation Counting Standardization of {sup 2}2NaCl by te CIEMAT/NIST method; Calibracion por Centelleo Liquido del ''22NaCl, mediante el metodo CIEMAT/NIST

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

1995-07-01

We describe a procedure for preparing a stable solution of ''22NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4 % and an overall uncertainty of 0.35 %. (Author) 4 refs.

Preparation of 'dead water' for low background liquid scintillation counting

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko; Niwa, Takeo; Kawai, Hiroshi

1987-01-01

'Dead water', low level tritiated water is indispensable to measure tritium concentration in environmental waters using a low background liquid scintillation counter. Water produced by combustion of natural gas, or deep sea water etc. are usually used for the above purpose. A new method of reducing tritium concentration in natural water has been introduced for preparation of 'dead water'. This method is to combine hydrogen-oxygen mixture produced by water electrolysis with hopcalite catalyzer at 700 deg C. Deep well water was electrolized up to 2/3 volume, and tritium concentration of recombined water was reduced to be about one third of that of the original one. (author)

A methodology for the optimization of the estimation of tritium in urine by liquid scintillation counting

International Nuclear Information System (INIS)

Joseph, S.; Kramer, G.H.

1982-10-01

A method has been designed to optimize liquid scintillation (LS) urinalysis with respect to sensitivity and cost. Three related factors, quench, sample composition and counting efficiency, were measured simultaneously and the results plotted in three dimensions to determine the optimum conditions for urinalysis. Picric acid was used to simulate quenching. Subsequent urinalysis experiments showed that quenching by picric acid was analogous to urine quenching. The optimization methodology was applied to ten commercial LS cocktails and a wide divergence in results was obtained. This method can also be used to optimize minimum detectable activities (MDA) but the results show that there is no fixed sample composition that can be used for all the various types of urine samples; however, it is possible to achieve general improvements of at least a factor of 2 in the MDA for Scintiverse (the only one tested for this particular application of the methodology)

Low-level flow counting of liquid chromatography column eluates

International Nuclear Information System (INIS)

Harding, N.G.L.; Farid, Y.; Stewart, M.J.

1982-01-01

The principal parameters which determine the operation of a high-resolution, high-sensitivity radioactive flow monitor are described: a) Sample preparation to ensure adequate recovery of radiolabelled sample, metabolites and internal standard. b) The instrument background count rate, when no sample or radiolabel is present in the flow cell, is a function of shielding and a reduction in noise obtained with a coincidence time below one microsecond. c) The minimum detectable amount of label depends upon the machine background, HPLC eluent and scintillator flow, whether or not packed flow cells are used, flow cell geometry, and the scintillator used. d) Three types of flow cell have been designed to cover the majority of HPLC and isotope applications. e) The performance of solid and liquid scintillators. It is shown that an instrument has been designed taking account of these parameters. The resulting design satisfies present high sensitivity counting requirements and maintains the resolution of current HPLC procedures when detection is by simultaneous flow radioassay and by optical methods. (orig.)

Scintillating properties of frozen new liquid scintillators

CERN Document Server

Britvich, G I; Golovkin, S V; Martellotti, G; Medvedkov, A M; Penso, G; Soloviev, A S; Vasilchenko, V G

1999-01-01

The light emission from scintillators which are liquid at room temperature was studied in the interval between $+20$~$^{\\circ}$C and $-120$~$^{\\circ}$C, where the phase transition from liquid to solid takes place. The light yield measured at $-120$~$^{\\circ}$C is about twice as much as that observed at $+20$~$^{\\circ}$C. By cooling the scintillator from $+20$~$^{\\circ}$C to $-120$~$^{\\circ}$C and then heating it from $-120$~$^{\\circ}$C to $+20$~$^{\\circ}$C, the light yield varies in steps at well defined temperatures, which are different for the cooling and heating processes. These hysteresis phenomena appear to be related to the solvent rather than to the dopant. The decay time of scintillation light was measured at $+20$~$^{\\circ}$C and $-120$~$^{\\circ}$C. Whilst at room temperature most of the light is emitted with a decay time of 6--8 ns, at $-120$~$^{\\circ}$C a slower component, with a decay time of 25--35 ns, becomes important.

Problems and precision of the alpha scintillation radon counting system

International Nuclear Information System (INIS)

Lucas, H.F.; Markuu, F.

1985-01-01

Variations in efficiency as large as 3% have been found for radon scintillation counting systems in which the photomultiplier tubes are sensitive to the thermoluminescent photons emitted by the scintillator after exposure to light or for which the resolution has deteriorated. The additional standard deviation caused by counting a radon chamber on multiple counting systems has been evaluated and the effect, if present, did not exceed about 0.1%. The chambers have been calibrated for the measurement of radon in air, and the standard deviation was equal to statistical counting error combined with a systematic error of 1.1%. 3 references, 2 figures, 2 tables

Standardization of 137 Cs+137m Ba by Liquid Scintillation

International Nuclear Information System (INIS)

Rodriguez, L.; Arcos, J.M., los; Grau Carles, A.

1995-09-01

A procedure for the preparation of a stable, homogeneous solution of ''137 Cs+''137m Ba, for use in liquid scintillation measurements, is described. Its count rate stability and spectral time evolution has been followed for several weeks. The solution has been standardised by the CIEMAT/NIST method in both Ultima-Gold and Insta-Gel, to a combined uncertainty lower than 0,51% (k=1)

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

International Nuclear Information System (INIS)

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

1988-01-01

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

Isotope Fractionation in Methane Reactions Studied by Gas Chromatography and Liquid Scintillation

DEFF Research Database (Denmark)

Andersen, Bertel Lohmann; Bidoglio, G.; Leip, A.

1997-01-01

Determination of C-14-marked methane by gas chromatography and liquid scintillation counting is shown to be useful in studies of isotope effects. Data on the specific activity is used to separate the contributions of (CH4)-C-14, and (CH4)-C-12 to the gas-chromatographic peak area. As an application...

The determination of the optimum counting conditions for a ZnS(Ag) scintillation detector

International Nuclear Information System (INIS)

Djurasevic, M.M.; Kandic, A.B.; Novkovic, D.N; Vukanac, I.S. . E-mail address of corresponding author: mirad@vin.bg.ac.yu; Djurasevic, M.M.)

2005-01-01

The methods that use scintillation counting with ZnS(Ag) scintillation detector are widely used for gross alpha activity determination. The common criteria for the selection of optimum counting condition for a ZnS(Ag) scintillation detector do not consider simultaneously operating voltage and discrimination level variation. In presented method a relationship between voltage and discrimination level is derived for counting efficiency. (author)

Quantitative determination of 14C(-)-epicatechin and 14C-rutin on the Uncaria plant by a two-step heterogeneous thin-layer chromatographic-liquid scintillation counting procedure

International Nuclear Information System (INIS)

Das, N.P.; Law, K.H.

1987-01-01

A simple, rapid, precise and relatively inexpensive thin-layer chromatographic method coupled to heterogeneous liquid scintillation counting procedure was used for the quantitation of radioactivity of biologically synthesized ( 14 C) flavonoids and other phenolic plant constituents. The two flavonoids, namely ( 14 C) rutin and ( 14 C) (-) -epicatechin, extracted from the plant Uncaria elliptica Roxb were separated on plastic thin-layer plates coated with silica gel using the two solvent systems : acetonitrile-acetic acid-water (8.5:0.5:1.5) and ethyl acetate-acetic acid-water (3:1:3). The respective spots on the plates that corresponded to the two flavonoids were cut out and eluted with 3 ml aliquots of methanol followed by direct addition of scintillation flour. This method gave 99 +- 2 per cent of the total count indicating the excellent elution procedure. The results were reproducible and showed linearity over the range of 0 - 35000 dpm. The elution efficiency by several other organic solvents were also investigated. (author). 19 refs., 4 tables

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

International Nuclear Information System (INIS)

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

1981-01-01

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

Inorganic liquid scintillator

International Nuclear Information System (INIS)

Pavlicek, Z.; Barta, C.; Jursova, L.

1986-01-01

An inorganic liquid scintillator is designed which contains 1 to 30 wt.% of an inorganic molecular compound as the basic active component; the compound contains a cation with an atomic number higher than 47 and a halogen anion. The basic inorganic component is dissolved in water or in an organic solvent in form of non-dissociated molecules or self-complexes in which the bond is preserved between the cation and anion components. The light yield from these scintillators ranges between 70 and 150% of the light yield of a standard organic scintillator based on toluene. They are advantageous in that that they allow to increase the water content in the sample to up to 100%. (M.D.)

Stability and counting losses of Li sup 36 CL samples in liquid scintillation measurements. Evaluacion de la estabilidad y perdidas de recuento de muestras de Li sup 36 CL en medidas por centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Grau, A.; Rodriguez, L.; Los Arcos, J.M.

1990-01-01

A systematic study of several factors concerning the liquid scintillation counting efficiency of Li{sup 36}CL samples in ethanolic solutions has been carried out. The stability of samples containing less than 1.2 Bq/{mu}l of Li{sup 36}Cl in ethanol, added to a toluene-based scintillator is enterely satisfactory. Samples with higher concentration show counting losses than can reach up to 29% of the optimal values along 24 hours. After regeneration of unstable samples by progressive ethanol dilution, the counting efficiency remains always lower than 98% of the best value. Nevertheless the counting rate obtained can be predicted as an exponential function of the dilution degree or activity concentration in the sample. The spectral degradation can be taken into account by defining a parameter, {delta}, wich allows to evaluate the counting loss correction in a sample as a rational function of {delta} (Author)

Polyethylene vials for liquid scintillation counters produced by the National Materials Research Institute

International Nuclear Information System (INIS)

Fiser, B.; Lukas, D.

1984-01-01

The properties were tested of polyethylene vials for liquid scintillation counters manufactured by the National Materials Research Institute. Liquid scintillation counter ISOCAP 300 by Nuclear Chicago was used for measuring. For unquenched samples, channel A was set up to 0.5-3.6 keV and channel B to 0.5-18 keV. The scintillation solution was prepared of toluene, 4 g PPO, 0.15 g POPOP per 1 l of toluene. CCl 4 was used as the quenching agent. Radioactive samples were prepared from 20 μl of standard solution of [ 3 H]-toluene with specific activity of 349 Bq/g. All measurements were made using a 7 ml scintillation solution into which radioactivity and possibly quenching agents were added. Potassium-free glass vials by SKLO UNION Teplice and thin-walled polyethylene vials by Nuclear Chicago were used for comparison. The background was measured, as were the time dependences of weight losses of the scintillation solution and carbon tetrachloride from the counting vials, changes in efficiency in channel B with time, changes in SCR with time and changes in the quenching curve with time. (E.S.)

Preparation of manganese salts of carboxylic acids labelled with ''54Mn and comparison with ''54 MnCl{sub 2} in liquid scintillation counting; Preparacion de sales manganosas de acidos alifaticos monocarboxilicos marcados con ''54 MnCl{sub 2} en medidas por centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Barquero, L.; Arcos Merino, J. M. los; Grau Malonda, A.

1992-07-01

Procedures for liquid scintillation sample preparation of manganese dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene. HISafe II. PCS, instagel. Dioxane-naphtalene and Toluene-alcohol. For comparison, Inorganic 54 MnCl-2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (Author)

Analytical method of Kr-85 determination, using cryogenic concentration and separation and liquid scintillation counting; Desarrollo del metodo de concentracion y se paracion criogenica cromatografica y medida radiactiva por centelleo liquido de Kr-85

Energy Technology Data Exchange (ETDEWEB)

Heras, M C; Perez, M M; Grau, A

1983-07-01

The method used in the Laboratory of the JEN for the determination of Kr-85 levels in gaseous effluents of nuclear power and in the atmosphere is described. Samples of air, collected in metallic cylinders, are introduced into a gas-solid chromatographic separation system which resolves Kr from the other air components. The separated Kr ia dissolved in a toluene based scintillation cocktail, and the Kr-85 content is determined by liquid scintillation counting. (Author)

Optimization of 14C liquid scintillation counting of plant and soil lipids to trace short term formation, translocation and degradation of lipids

International Nuclear Information System (INIS)

Wiesenberg, G.L.B.; Gocke, M.; Yakov Kuzyakov

2010-01-01

Two powerful approaches are frequently used to trace incorporation and degradation of plant derived C in soil: 14 C labelling/chasing and analysis of lipid composition. In this study, we coupled these approaches in order to trace short term incorporation of plant derived lipids into rhizosphere and non-rhizosphere soil. Methodological optimization was required and implied 14 C liquid scintillation counting improvement for plant lipid extracts taking into account organic solvents, solvent-to-scintillation cocktail ratio, and amount of lipids. Following method optimization, 14 C data of fatty acids indicated a notable contribution of root derived lipids to rhizosphere and non-rhizosphere soil. Coupling of 14 C labelling/chasing with lipid analysis is a powerful and cheap approach for tracing of root derived C in soil allowing for estimation of C budget, for determination of C formation and translocation within plants and from plant to soil, as well as for identification of short term dynamics of specific compound classes within soil. (author)

Automation of a Beckman liquid scintillation counter for data capture and data-base management

International Nuclear Information System (INIS)

Neil, W.; Irwin, T.J.; Yang, J.J.

1988-01-01

A software package for the automation of a Beckman LS9000 liquid scintillation counter is presented. The package provides effective on-line data capture (with a Perkin Elmer 3230 32-bit minicomputer), data-base management, audit trail and archiving facilities. Key features of the package are rapid and flexible data entry, background subtraction, half-life correction, ability to queue several sample sets pending scintillation counting, and formatted report generation. A brief discussion is given on the development of customized data processing programs. (author)

(Alpha-) quenching temperature dependence in liquid scintillator

Energy Technology Data Exchange (ETDEWEB)

Soerensen, Arnd; Lozza, Valentina; Krosigk, Belina von; Zuber, Kai [Institut fuer Kern- und Teilchenphysik, TU Dresden (Germany)

2015-07-01

Liquid scintillator (LS) is an effective and promising detector material, which is and will be used by many small and large scale experiments. In order to perform correct signal identification and background suppression, a very good knowledge of LS properties is crucial. One of those is the light yield from alpha particles in liquid scintillator. This light output strongly quenched, approx. 10 times compared to that of electrons, and has been precisely studied at room temperature for various LS. Big scintillator experiments, such as SNO+ and maybe future large scale detectors, will operate at different temperatures. While a strong temperature dependence is well known for solid state scintillators, due to the different scintillation process, a quenching temperature dependence in LS is usually assumed negligible. On the other hand, inconsistencies in between measurements are often explained by potential temperature effects. This study investigates LAB based liquid scintillator with an intrinsic, dissolved alpha emitter and its behaviour with temperature change. In a small, cooled and heated setup, a stabilized read-out with two PMTs is realised. First results are presented.

Evaluation of the uncertainty for the efficiency curve determination of 210Pb by liquid scintillation

International Nuclear Information System (INIS)

Sampaio, C.S.; Sousa, W.O.; Dantas, B.M.

2014-01-01

Methodologies for the evaluation of uncertainties associated with the determination of the efficiency curve of 210 Pb by liquid scintillation counting (LSC) are presented. No statistical difference were found when compared the uncertainties of the curves that represented the counting net before and after the secular equilibrium between 210 Pb and 210 Bi, nether when compared the curves when counting only 210 Pb and the curve with the total count of 210 Pb and 210 Bi, for the same time interval after precipitation. (author)

Development of new Polysiloxane Based Liquid Scintillators

Energy Technology Data Exchange (ETDEWEB)

Dalla Palma, M.; Quaranta, A. [Department of Industrial Engineering, University of Trento,Via Sommarive, 9, 38123 Trento (Italy); INFN, Laboratori Nazionali di Legnaro,Viale dell' Universita, 2, 35020 Legnaro - Padova (Italy); Gramegna, F.; Marchi, T.; Cinausero, M. [INFN, Laboratori Nazionali di Legnaro,Viale dell' Universita, 2, 35020 Legnaro - Padova (Italy); Carturan, S.; Collazuol, G.; Checchia, C. [INFN, Laboratori Nazionali di Legnaro,Viale dell' Universita, 2, 35020 Legnaro - Padova (Italy); Department of Physics and Astronomy, University of Padova, Via Marzolo, 8, 35131 Padova (Italy); Degerlier, M. [Department of Physics, Nevsehir Haci Bektas Veli University, Science and Art Faculty, 50300 Nevsehir (Turkey)

2015-07-01

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

Investigation of organic liquid-scintillator optical properties

Energy Technology Data Exchange (ETDEWEB)

Winter, Juergen; Feilitzsch, Franz von; Goeger-Neff, Marianne; Lewke, Timo; Meindl, Quirin; Oberauer, Lothar; Potzel, Walter; Todor, Sebastian; Wurm, Michael [Physik Department E15, Technische Universitaet Muenchen, James-Franck-Str., 85748 Garching (Germany); Marrodan Undagoitia, Teresa [Physik Department E15, Technische Universitaet Muenchen, James-Franck-Str., 85748 Garching (Germany); Physik-Institut, Universitaet Zuerich (Switzerland)

2009-07-01

The characterization of different organic liquid-scintillator mixtures is an important step towards the design of a large-scale detector such as LENA (Low Energy Neutrino Astronomy). Its physics goals, extending from particle and geological to astrophysical issues, set high demands on the optical properties of the liquid scintillator. Therefore, small-scale experiments are carried out in order to optimize the final scintillator mixture. PXE, LAB, and dodecane are under consideration as solvents. Setups for the determination of scintillator properties are presented, such as attenuation length, light yield, emission spectra, fluorescence decay times, and quenching factors. Furthermore, results are discussed.

A liquid scintillation counter specifically designed for samples deposited on a flat matrix

International Nuclear Information System (INIS)

Potter, C.G.; Warner, G.T.

1986-01-01

A prototype liquid scintillation counter has been designed to count samples deposited as a 6x16 array on a flat matrix. Applications include the counting of labelled cells processed by a cell harvester from 96-well microtitration plates onto glass fibre filters and of DNA samples directly deposited onto nitrocellulose or nylon transfer membranes (e.g. 'Genescreen' NEN) for genetic studies by dot-blot hybridisation. The whole filter is placed in a bag with 4-12 ml of scintillant, sufficient to count all 96 samples. Nearest-neighbour intersample cross talk ranged from 0.004% for 3 H to 0.015% for 32 P. Background was 1.4 counts/min for glass fibre and 0.7 counts/min for 'Genescreen' in the 3 H channel: for 14 C the respective figures were 5.3 and 4.3 counts/min. Counting efficiency for 3 H-labelled cells on glass fibre was 54%(E 2 /B=2053) and 26% for tritiated thymidine spotted on 'Genescreen'(E 2 /B=980). Similar 14 C samples gave figures on 97%(E 2 /B=1775) and 81(E 2 B=1526) respectively. Electron emission counting from samples containing 125 I and 51 Cr was also possible. (U.K.)

Liquid scintillation counting standardization of 125I in organic and inorganic samples by the CIEMAT/NIST method; Calibracion por centelleo liquido del 125I en muestras inorganicas y organicas, mediante el metodo CIEMAT/NIST

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

1994-07-01

The liquid scintillation counting standardization of organic and inorganic samples of ''I25I by the CIEMAT/NIST method using five different scintillators is described. The discrepancies between experimental and computed efficiencies are lower than 1.4% and 1.7%, for inorganic and organic samples, respectively, in the interval 421-226 of quenching parameter. Both organic and inorganic solutions have been standardized in terms of activity concentration to an overall uncertainty of 0.76%. (Author) 14 refs.

Measurement of 103mRh produced by the 103Rh(γ,γ')103mRh reaction with liquid scintillation counting

International Nuclear Information System (INIS)

Sekine, T.; Yoshihara, Kenji; Pavlicsek, I.; Lakosi, L.; Veres, A.

1989-01-01

A liquid scintillation counting technique was applied to measure the isotope 103m Rh (half life = 56.12 min) which is difficult to detect because its γ-ray is of low energy and low emission probability. Tris-(2,4-pentanedionato)rhodium(III) (Rh(acac) 3 ) was irradiated with bremsstrahlung of accelerated 3.2 MeV electrons by LINAC. The method has given a reliable calibration curve for the determination of 103m Rh radioactivity below Rh(acac) 3 concentrations of 2 mM. The integrated cross section of 103 Rh(γ,γ') 103m Rh determined by this method was found to be 6.8±3.4 μb MeV at 3.2 MeV. (author) 8 refs.; 5 figs

Standardization of 137mCs+137mBa by Liquid Scintillation

International Nuclear Information System (INIS)

Rodriguez, L.; Los Arcos, J.M.; Grau, A.

1995-01-01

A procedure for the preparation of a stable, homogeneous solution of 137Cs+''137mBa, for use in liquid scintillation measurements, is described. Its count rate stability and spectral time evolution has been followed for several weeks. The solution has been standardised by the CIEMAT/NIST method in both Ultima-Gold and Insta-Gel, to a combined uncertainty lower than 0,51 % (k=l). (Author) 5 refs

Comparison of analysis techniques by liquid scintillation and Cerenkov Effect for {sup 40}K quantification in aqueous samples; Comparacion de las tecnicas de analisis por centelleo liquido y efecto Cerenkov para la cuantificacion {sup 40}K en muestras acuosas

Energy Technology Data Exchange (ETDEWEB)

Miranda C, L.; Davila R, J. I.; Lopez del R, H.; Mireles G, F., E-mail: lilimica20@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

2015-09-15

In this work the counting by liquid scintillation and Cerenkov Effect to quantify {sup 40}K in aqueous samples was used. The performance of both techniques was studied by comparing the response of three commercial liquid scintillation OptiPhase HiSafe 3, Ultima Gold Ab and OptiPhase TriSafe, the vial type and presentation conditions of the sample for counting. In liquid scintillation, the ability to form homogeneous mixtures depended on the ionic strength of the aqueous solutions. The scintillator OptiPhase HiSafe 3 showed a greater charge capacity for solutions with high ionic strength (<3.4), while the scintillator OptiSafe TriSafe no form homogeneous mixtures for solutions of ionic strength higher than 0.3. Counting efficiencies for different proportions of sample and scintillator near 100% for the scintillators OptiSafe HiSafe 3 and Ultima Gold Ab were obtained. In the counting by Cerenkov Effect, the efficiency and sensitivity depended of the vial type; polyethylene vials were more suitable for counting that the glass vials. The sample volume had not significant effect on counting efficiency, obtaining an average value of 44.8% for polyethylene vials and 37.3% for glass vials. Therefore, the liquid scintillation was more efficient and sensitive for the measurement of {sup 40}K in aqueous solutions. (Author)

222Rn determination in water and brine samples using liquid scintillation spectrometry

International Nuclear Information System (INIS)

Oliveira, Thiago C.; Oliveira, Arno H.

2017-01-01

Liquid scintillation spectrometry (LSC) is the most common technique used for 222 Rn determination in environmental aqueous sample. In this study, the performance of water-miscible (Ultima Gold AB) and immiscible (Optiscint) liquid scintillation cocktails has been compared for different matrices. 241 Am, 90 Sr and 226 Ra standard solutions were used for LSC calibration. 214 Po region was defined as better for both cocktails. Counting efficiency of 76 % and optimum PSA level of 95 for Ultima Gold AB cocktail, and counting efficiency of 82 % and optimum PSA level of 85 for Optiscint cocktail were obtained. Both cocktails showed similar results when applied for 222 Rn activity determination in water and brine samples. However the Optiscint is recommended due to its quenching resistance. Limit of detection of 0.08 and 0.06 Bq l -1 were obtained for water samples using a sample:cocktail ratio of 10:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. Limit of detection of 0.08 and 0.04 Bq l -1 were obtained for brine samples using a sample:cocktail ratio of 8:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. (author)

Liquid scintillation counting of calcium-45 in plant and soil material

International Nuclear Information System (INIS)

Waller, S.S.; Dodd, J.D.

1977-01-01

The recovery efficiencies of 45 Ca, for plant material using dry ashing with HCL as the extractant, and for soils using column extraction with MgCl 2 as the extractant, have been determined. The extraction and detection procedures, using available scintillation solvent systems, are given and show a combination of a high counting efficiency with high recovery efficiencies. The extraction procedures are simple, involving minimal operator time, and allow simultaneous 45 Ca determination in both plant and soil material. Both extraction procedures exhibit good reproducibility over a wide range of specific activities while being relatively insensitive to quenching and carrier calcium normally encountered in plant and soil material. These procedures are particularly useful in ecological studies requiring the examination of a large number of plant and/or soil samples over a wide range of radioactive concentrations. (U.K.)

Discriminator setting and cocktail preparation for analysis of alpha and beta emitters in aqueous solution using liquid scintillation counter

International Nuclear Information System (INIS)

Zaini Hamzah; Masitah Alias; Zaharudin Ahmad

2011-01-01

Liquid scintillation counting (LSC) is not only being used to measure pure beta emitters, but it can be used to measure both alpha and beta emitters simultaneously. Measurement of alpha and beta emitters in aqueous solution is done using a single sample. For the sample preparation, colorless detergent or emulsifier was used to incorporate the water into an organic based scintillator to produce a clear homogeneous solution, since this is the best form to give the highest count rate and detection efficiency. The instrument also need some attention, where after calibration, the LSC was set for the discriminator level which is suitable for measurement of both alpha and beta radiations. In this study, the focus is on the development of the best scintillation cocktail and establishes the best discriminator setting. From this study the best proportion of scintillation cocktail is 2:4:4 for water, toluene, and Triton-N101 (emulsifier) respectively and the best discriminator setting for alpha and beta counting are 120. (author)

Measuring techniques for environmental sup 3 H, sup 14 C and sup 222 Rn by liquid scintillation counter

Energy Technology Data Exchange (ETDEWEB)

Takata, Shigeru; Saito, Masaaki (Tokyo Metropolitan Isotope Research Center (Japan))

1991-02-01

Measuring techniques for environmental {sup 3}H, {sup 14}C and {sup 222}Rn with a liquid scintillation counter have been studied. {sup 3}H in environmental water was enriched by electrolysis and measured with a low background liquid scintillation counter. By this technique, {sup 3}H concentration of ground water, river water, sea water and rain water at Tokyo was founded to be 0.1 {approx} 2.5 Bq/1. {sup 14}C in taurine and ethyl-alcohol was measured directly liquid scintillation counter. By this {sup 14}C measuring, natural products, contain low level {sup 14}C, were distinguished from synthesised products contain no {sup 14}C. {sup 222}Rn in toluene extracted from environmental water or air was measured by scintillation pulse interval analysis method. By this technique, {sup 222}Rn was able to be measured under very low background counting rate, 0.03cpm, and high efficiency. (author).

Performance of 2000CA/LL and 2260XL liquid scintillation spectrometers for low-level tritium and carbon-14 analyses

International Nuclear Information System (INIS)

Rozanski, K.; Stichler, W.; Schwarz, P.

1991-01-01

The performance of two commercially available liquid scintillation spectrometers for low-level counting of 3 H and 14 C has been investigated. Two models of new technology Tri-Carb spectrometers from the Packard Instrument Company were tested: the 2000CA/LL and 2260XL. The measurements revealed a superior 3 H performance of the 2000CA/LL equipment owing to its substantially higher counting efficiency. Results for 14 C are less conclusive and depend on the configuration of the counting parameters selected. A comparison of three commercially available scintillation cocktails for tritium assay in water samples revealed a superior performance for PicoFluor LLT. (Author)

Removal of impurities from environmental water samples for tritium measurement by means of liquid scintillation counter

International Nuclear Information System (INIS)

Sakuma, Yoichi; Noda, Mitsuyasu

2000-01-01

Tritium concentration in environmental water samples is usually measured by means of liquid scintillation counting. Before the counting distillation operation is necessarily required to remove impurities, which have possibility of bad influence on the measurement, from the samples. But the operation usually takes long time and it is also troublesome. If you could simplify the purification process, you would be much easily able to measure it. Then, we have studied the probability of replacement the process by filtration aiming to simplify the procedure. We prepared several environmental water samples and also several water samples added quenching materials. These samples were purified by means of the distillation and the filtration and the impurities in them were examined. The purified samples were mixed with scintillation cocktail and the tritium concentration was measured. We added small amount of tritium in the same samples and investigated their scintillation spectra and their ESCR values in order to compare the two purification methods. Two kinds of filters were used for the filtration: 0.45 μm and 0.1 μm pore sized membrane filters. The liquid scintillation counter was LB-3 produced by Aloka Co. and Ltd. The scintillation cocktail was Ultima Gold LLT made by Packard Instrument Co and Ltd. The vial was Polyvial 145 LSD made by Zinsser Analytic Co. and Ltd. As the result, there was no significant difference between the two purification methods then the filtration method is feasible instead of the distillation. (author)

Optimization of the detector and associated electronics used for high-resolution liquid-scintillation alpha spectroscopy

International Nuclear Information System (INIS)

Thorngate, J.H.; Christian, D.J.

1977-01-01

The performance of various reflector geometries, light coupling liquids, photomultiplier tubes, preamplifiers and linear amplifiers were compared and the configuration found that optimized the combination of pulse-height resolution and pulse-shape discrimination. The best combination used a hemispherical reflector, filled with distilled water, coupled to an 8575 photomultiplier tube, the output of which was conditioned by a special integrating preamplifier and a double-delay-line linear amplifier. Careful choice of the scintillator, sample preparation procedures, and electronic apparatus can produce liquid-scintillation alpha spectroscopy with a pulse-height resolution of 300 keV, or less, and, by using pulse-shape discrimination, background levels as low as 0.01 counts/min. (author)

Partitioning of krypton-85 in liquid scintillation cocktail

International Nuclear Information System (INIS)

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 β - 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

Method validation and verification in liquid scintillation counting using the long-term uncertainty method (LTUM) on two decades of proficiency test data

International Nuclear Information System (INIS)

Verrezen, F.; Vasile, M.; Loots, H.; Bruggeman, M.

2017-01-01

Results from proficiency tests gathered over the past two decades by the laboratory for low level radioactivity measurements for liquid scintillation counting of 3 H (184 results) and 14 C (74 results) are used to verify the validated measurement methods used by the laboratory, in particular the estimated uncertainty budget of the method and its reproducibility and stability. A linear regression approach is used for the analysis of the results, described in the literature as the long term uncertainty in measurement method. The present study clearly indicates the advantages of using proficiency test results in identifying possible constant or proportional bias effects as well as the possibility to compare the laboratory performance with the performance of peer laboratories. (author)

Pulse-duration discrimination for increasing counting characteristic plateau and for improving counting rate stability of a scintillation counter

International Nuclear Information System (INIS)

Kuz'min, M.G.

1977-01-01

For greater stability of scintillation counters operation, discussed is the possibility for increasing the plateau and reducing its slope. Presented is the circuit for discrimination of the signal pulses from input pulses of a photomultiplier. The counting characteristics have been measured with the scintillation detectors being irradiated by different gamma sources ( 60 Co, 137 Cs, 241 Am) and without the source when the scintillation detector is shielded by a tungsten cylinder with a wall thickness of 23 mm. The comparison has revealed that discrimination in duration increase the plateau and reduces its slope. Proceeding from comparison of the noise characteristics, the relationship is found between the noise pulse number and gamma radiation energy. For better stability of the counting rate it is suggested to introduce into the scintillation counter the circuit for duration discrimination of the output pulses of a photomultiplier

Large liquid-scintillator trackers for neutrino experiments

CERN Document Server

Benussi, L; D'Ambrosio, N; Déclais, Y; Dupraz, J P; Fabre, Jean-Paul; Fanti, V; Forton, E; Frekers, D; Frenkel, A; Girerd, C; Golovkin, S V; Grégoire, G; Harrison, K; Jonkmans, G; Jonsson, P; Katsanevas, S; Kreslo, I; Marteau, J; Martellotti, G; Martínez, S; Medvedkov, A M; Moret, G; Niwa, K; Novikov, V; Van Beek, G; Penso, G; Vasilchenko, V G; Vuilleumier, J L; Wilquet, G; Zucchelli, P; Kreslo, I E

2002-01-01

Results are given on tests of large particle trackers for the detection of neutrino interactions in long-baseline experiments. Module prototypes have been assembled using TiO$_2$-doped polycarbonate panels. These were subdivided into cells of $\\sim 1$~cm$^2$ cross section and 6~m length, filled with liquid scintillator. A wavelength-shifting fibre inserted in each cell captured a part of the scintillation light emitted when a cell was traversed by an ionizing particle. Two different fibre-readout systems have been tested: an optoelectronic chain comprising an image intensifier and an Electron Bombarded CCD (EBCCD); and a hybrid photodiode~(HPD). New, low-cost liquid scintillators have been investigated for applications in large underground detectors. Testbeam studies have been performed using a commercially available liquid scintillator. The number of detected photoelectrons for minimum-ionizing particles crossing a module at different distances from the fibre readout end was 6 to 12 with the EBCCD chain and ...

Validation of Analysis Method of pesticides in fresh tomatoes by Gas Chromatography associated to a liquid scintillation counting

International Nuclear Information System (INIS)

Dhib, Ahlem

2011-01-01

Pesticides are nowadays considered as toxic for human health. The maximum residues levels (MRL) in foodstuff are more and more strict. Therefore, selective analytical techniques are necessary for their identification and their quantification. The aim of this study is to set up a multi residue method for the determination of pesticides in tomatoes by gas chromatography with μECD detector (GC/μECD) associated to liquid scintillation counting. A global analytical protocol consisting of a QuECHERS version of the extraction step followed by purification step of the resulting extract on a polymeric sorbent was set up. The 14 C-chloropyrifos used as an internal standard proved excellent to control the different steps needed for the sample preparation. The method optimized is specific, selective with a recovery averaged more than 70 pour cent, repetitive and reproducible. Although some others criteria need to be checked regarding validation before its use in routine analysis, the potential of the method has been demonstrated.

Radiocarbon dating methods using benzene liquid scintillation

International Nuclear Information System (INIS)

Togashi, Shigeko; Matsumoto, Eiji

1983-01-01

The radiocarbon dating method using benzene liquid scintillation is reported in detail. The results of measurement of NBS oxalic acid agree with the recommended value, indicating that isotopic fractionation during benzene synthesis can be negligible. Ten samples which have been already measured by gas counter are dated by benzene liquid scintillation. There is no significant difference in age for the same sample between benzene liquid scintillation and gas counters. It is shown that quenching has to be corrected for the young sample. Memory effect in stainless steel reaction vessel can be removed by using an exchangeable inner vessel and by baking it in the air. Using this method, the oldest age that can be measured with 2.3 g carbon is 40,000 years B.P. (author)

Operation of CdZnTe Semiconductor Detectors in Liquid Scintillator for the COBRA Experiment

International Nuclear Information System (INIS)

Oldorf, Christian

2015-08-01

COBRA, the Cadmium-Zinc-Telluride O-neutrino double-Beta Research Apparatus, is an experiment aiming for the measurement of the neutrinoless double beta decay with several isotopes, in particular 116 Cd, 106 Cd and 130 Te. A highly granular large scale experiment with about 400 kg of CdZnTe semiconductor detectors is currently under development. To provide evidence for the neutrinoless double beta decay of 116 Cd, a background rate in the order of 10 -3 counts/keV/kg/a is needed to achieve the required half-life sensitivity of at least 2 . 10 26 years. To reach this target, the detectors have to be operated in a highly pure environment, shielded from external radiation. Liquid scintillator is a promising candidate as a circum fluent replacement for the currently used lacquer. Next to the function as highly pure passivation material, liquid scintillator also acts as a neutron shield and active veto for external gammas. Within this thesis, the design, construction and assembly of a test set-up is described. The operation of four CdZnTe detectors after several years of storage in liquid scintillator is demonstrated. Next to extensive material compatibility tests prior to the assembly, the commissioning of the set-up and the characterization of the detectors are shown. Finally, results concerning the background reduction capability of liquid scintillator and the detection of cosmic muons are presented and compared to a Monte Carlo simulation.

Fluorescent organic dyes as radiation converters in scintillation counting and laser techniques

International Nuclear Information System (INIS)

Guesten, H.

1989-01-01

PMP (1-phenyl-3-mesityl-2-pyrazoline) was selected as color quenching from the category of the sterically hindered 1,3-diphenyl-2-pyrazoline by means of comparative optimization between photo-physical and scintillation-spectroscopic and chemical properties and the costs of synthesis. It is applied in liquid scintillation detectors for the detection of β (T, C-14) and in large-volume liquid scintillators for the detection of neutrinos (Rutherford Lab.). (HP) [de

New liquid scintillators for fiber-optic applications

International Nuclear Information System (INIS)

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

1981-01-01

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

Well scintillation counting systems for nuclear medicine applications in developing countries

International Nuclear Information System (INIS)

1977-01-01

This report of a consultants' meeting, organized by the Medical Applications Section of the Division of Life Sciences, IAEA, during the period 23-25 May 1977, examines well scintillation counting systems in the light of the requirements of laboratories in developing countries. It has three facets: 1) identification of the most rewarding applications of nuclear medicine techniques, 2) identification of favourable design attributes of instruments used in such applications, and 3) development of maintenance strategies to assure reliable performance of the instruments once put into service. Some characteristics of commercially available well scintillation counting systems are given

Radiocarbon dating of samples for archaeologic and geologic interesting by liquid scintillation spectrometry with low background radiation

International Nuclear Information System (INIS)

Pessenda, L.C.R.; Camargo, P.B. de

1991-01-01

An analytical system for radiocarbon dating of environmental samples using low level liquid scintillation counting spectrometry was developed at the Center for Nuclear Energy in Agriculture, University of Sao Paulo. Physical and chemical pretreatment and benzene synthesis of samples, counting procedure, optimization of analytical parameters and laboratory intercomparison with radiocarbon laboratories of Center for Applied Isotope Studies, University of Georgia, USA and University of Waterloo, Canada, are described. (author)

A scintillation detector signal processing technique with active pileup prevention for extending scintillation count rates

International Nuclear Information System (INIS)

Wong, W.H.; Li, H.

1998-01-01

A new method for processing signals from scintillation detectors is proposed for very high count-rate situations where multiple-event pileups are the norm. This method is designed to sort out and recover every impinging event from multiple-event pileups while maximizing the collection of scintillation signal for every event to achieve optimal accuracy in determining the energy of the event. For every detected event, this method cancels the remnant signals from previous events, and excludes the pileup of signals from following events. With this technique, pileup events can be recovered and the energy of every recovered event can be optimally measured despite multiple pileups. A prototype circuit demonstrated that the maximum count rates have been increased by more than 10 times, comparing to the standard pulse-shaping method, while the energy resolution is as good as that of the pulse shaping (or the fixed integration) method at normal count rates. At 2 x 10 6 events/sec for NaI(Tl), the true counts acquired are 3 times more than the delay-line clipping method (commonly used in fast processing designs) due to events recovered from pileups. Pulse-height spectra up to 3.5 x 10 6 events/sec have been studied

A new digital method for high precision neutron-gamma discrimination with liquid scintillation detectors

International Nuclear Information System (INIS)

Nakhostin, M

2013-01-01

A new pulse-shape discrimination algorithm for neutron and gamma (n/γ) discrimination with liquid scintillation detectors has been developed, leading to a considerable improvement of n/γ separation quality. The method is based on triangular pulse shaping which offers a high sensitivity to the shape of input pulses, as well as, excellent noise filtering characteristics. A clear separation of neutrons and γ-rays down to a scintillation light yield of about 65 keVee (electron equivalent energy) with a dynamic range of 45:1 was achieved. The method can potentially operate at high counting rates and is well suited for real-time measurements.

{sup 222}Rn determination in water and brine samples using liquid scintillation spectrometry

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Thiago C.; Oliveira, Arno H., E-mail: oliveiratco2010@gmail.com [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear; Monteiro, Roberto P.G.; Moreira, Rubens M., E-mail: rpgm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Liquid scintillation spectrometry (LSC) is the most common technique used for {sup 222}Rn determination in environmental aqueous sample. In this study, the performance of water-miscible (Ultima Gold AB) and immiscible (Optiscint) liquid scintillation cocktails has been compared for different matrices. {sup 241}Am, {sup 90}Sr and {sup 226}Ra standard solutions were used for LSC calibration. {sup 214}Po region was defined as better for both cocktails. Counting efficiency of 76 % and optimum PSA level of 95 for Ultima Gold AB cocktail, and counting efficiency of 82 % and optimum PSA level of 85 for Optiscint cocktail were obtained. Both cocktails showed similar results when applied for {sup 222}Rn activity determination in water and brine samples. However the Optiscint is recommended due to its quenching resistance. Limit of detection of 0.08 and 0.06 Bq l{sup -1} were obtained for water samples using a sample:cocktail ratio of 10:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. Limit of detection of 0.08 and 0.04 Bq l{sup -1} were obtained for brine samples using a sample:cocktail ratio of 8:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. (author)

An efficient energy response model for liquid scintillator detectors

Science.gov (United States)

Lebanowski, Logan; Wan, Linyan; Ji, Xiangpan; Wang, Zhe; Chen, Shaomin

2018-05-01

Liquid scintillator detectors are playing an increasingly important role in low-energy neutrino experiments. In this article, we describe a generic energy response model of liquid scintillator detectors that provides energy estimations of sub-percent accuracy. This model fits a minimal set of physically-motivated parameters that capture the essential characteristics of scintillator response and that can naturally account for changes in scintillator over time, helping to avoid associated biases or systematic uncertainties. The model employs a one-step calculation and look-up tables, yielding an immediate estimation of energy and an efficient framework for quantifying systematic uncertainties and correlations.

New scintillating media based on liquid crystals for particle detectors

International Nuclear Information System (INIS)

Barnik, M.I.; Yudin, S.G.; Vasil'chenko, V.G.; Golovkin, S.V.; Medvedkov, A.M.; Solovjev, A.S.

2000-01-01

The study results of optical, photoluminiscent and scintillation properties of a liquid crystal 4-pentyl-4'-cyanobiphenyl are presented. The scintillation light output of this liquid crystal is about 35% of crystal anthracene, its main decay time constants are 4 and 14 ns, and the maximum of light emission spectrum is about 400 nm. The light output of a dissolution of green emitting light scintillation dopant R6 in the liquid crystal is about 120% of crystal anthracene. The light output of the frozen dissolution measured at -112 deg. C is about 2.5 times higher as observed at +20 deg. C. In the uniaxially oriented liquid crystal, the predominant intensity direction of emitted light is pointed perpendicular to the liquid crystal director and an appreciable part of the emitted light is elliptically polarized. The possibility to use scintillation properties of liquid crystals is considered both for the improvement of existing particle detector characteristics and for the creation of new gated particle detectors

New scintillating media based on liquid crystals for particle detectors

CERN Document Server

Barnik, M I; Vasilchenko, V G; Golovkin, S V; Medvedkov, A M; Soloviev, A S

2000-01-01

The study results of optical, photoluminiscent and scintillation properties of a liquid crystal 4-pentyl-4'-cyanobiphenyl are presented. The scintillation light output of this liquid crystal is about 35% of crystal anthracene, its main decay time constants are 4 and 14 ns, and the maximum of light emission spectrum is about 400 nm. The light output of a dissolution of green emitting light scintillation dopant R6 in the liquid crystal is about 120% of crystal anthracene. The light output of the frozen dissolution measured at -112 deg. C is about 2.5 times higher as observed at +20 deg. C. In the uniaxially oriented liquid crystal, the predominant intensity direction of emitted light is pointed perpendicular to the liquid crystal director and an appreciable part of the emitted light is elliptically polarized. The possibility to use scintillation properties of liquid crystals is considered both for the improvement of existing particle detector characteristics and for the creation of new gated particle detectors.

The accurate measurement of the disintegration rate of 55Fe using an internal liquid scintillation counter

International Nuclear Information System (INIS)

Botha, S.M.

1979-01-01

As the well-known 4πX-γ-coincidence method cannot be used directly to find the disintegration rate of 55 Fe, another method was developed in which a tracer nuclide, possessing coincident gamma radiation, was used. It was now possible to determine the disintegration rate indirectly by the coincidence method using an internal liquid scintillation counter. 54 Mn and 51 Cr which lie in the immediate vicinity of iron in the series of nuclides, are suitable tracers. They are also electron capture nuclides, but decaying to an excited state, were counted by the 4πX-γ-coincidence method. A mixed source, containing 55 Fe and the tracer, was also counted by the coincidence method so that the 4π-counting rate of 55 Fe was obtained as function of the tracer's counting efficiency. It was also essential to find a relationship between the counting efficiencies of the liquid scintillation counter for 55 Fe and the tracer. This relationship is called the effeciency function. Efficiency functions were calculated for 55 Fe and 54 Mn as well as for 55 Fe and 51 Cr. Finally the radioactive concentration of a solution of 55 Fe had been carefully determined by using 54 Mn and 51 Cr tracers. The results for the two different tracers agreed within the statistical uncertainty of 0,4%. The systematic uncertainty on the final results was estimated as 0,17%

A comparative study of 19-iodocholesterol-''125I 3-acetate and Na''125I in liquid scintillation measurements

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J.M.; Grau Carles, A.

1994-01-01

A comparative study of performance of 19-iodocholesterol-''125I 3-acetate and sodium iodine samples labelled with ''125 I is presented for liquid scintillation counting measurements. Quench effect, count rate stability and spectral evolution of samples have been followed for several weeks in Toluene, Hisafe II, Instagel, Dioxane-naphthalene and Toluene-alcohol scintillators. Organic samples have negligible quench effect in the interval of I''-concentration of 0-90 ug and inorganic samples only show a very small variation, lower than 12%, for Dioxane-naphthalene, in the same range of concentration. Satisfactory stability is obtained in general for both, organic and inorganic samples, but small counting losses, 0.03% for 19-iodocholesterol-''125I 3-acetate samples in Toluene-alcohol and 0.04% for Na''125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs

Low level liquid scintillation analysis for environmental and biomedical quantitation

International Nuclear Information System (INIS)

Kessler, M.J.

1991-01-01

Over the past five years low level liquid scintillation counting has become increasing popular because of the large number of applications which can be performed using this technique. These applications include environmental monitoring ( 3 H, 90 Sr/ 90 Y, etc.), radiocarbon dating (for age determination to 50,000 years), food adulteration studies (alcohol and beverage industries), radon monitoring (air/water), nuclear power plant monitoring (low level 3 H) and metabolism studies (pharmaceutical research). These applications can be performed with either a dedicated low level LSC or using a standard liquid scintillation counter in conjunction with the new technique of time-resolved LSC (TR-LSC). This technique when used on a standard LSC reduces the instrument background without substantially effecting the background, thus increasing the performance (E 2 /B) of the LSC. Data will be presented for each of the applications mentioned above, comparing the standard LSC and the new TR-LSC techniques. The optimization of the samples for each of these applications will be explored in detail with experimental results. In conclusion, by using the TR-LSC technique in conjunction with a standard LSC the performance of the standard LSC can be increased substantially without dedicating the LSC to doing only low level samples

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-21

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

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

International Nuclear Information System (INIS)

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

2016-01-01

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

A flowrate measurement method by counting of radioactive particles suspended in a liquid

International Nuclear Information System (INIS)

Daniel, G.

1983-04-01

By external counting of fine #betta# emitting radioactive particles suspended in a liquid, the flowrate in a system of pipes can be measured. The study comprises three phases: 1. - The hydraulic validity of the method is demonstrated in laminar as well as in turbulent flow under certain conditions of particles size and density and of liquid viscosity. 2. - Radioactive labelling of microspheres of serumalbumin or ion exchange resins with indium 113m delivered by a generator Tin 113 → Indium 113m. 3. - Counting with a scintillation detector: a method of threshold overstepping is experimented with a mechanical or electronic simulator; the statistical study of particle superposition under the detector enables a correction for the resulting counting losses to be proposed. The method provides absolute measurements, but is particularly suitable to measure relative flowrates in a hydraulic network. It can be continuous and does not perturb the flow and the network. The accuracy of the method is analysed in details [fr

Recent advances in low-level β-counting by liquid scintillation instrumentation

International Nuclear Information System (INIS)

Verzilov, Yu.; Maekawa, Fujio; Oyama, Yukio; Maekawa, Hiroshi

1995-01-01

This work attempts to solve problems for measurement 3 H and 32 P activity. A measurement of tritium activity in materials is desired for neutron experiments such as a fusion reactor blanket experiment and a neutron flux monitor with 6 Li(n,α) 3 H reaction. In such studies, lithium-containing pellets are usually irradiated by neutrons and the tritium produced in them is measured with a liquid scintillation counter. Tritium technique for Li 2 CO 3 is the subject of interest in the present study because this compound is well soluble and easy to use it. The 32 P is important nuclide in the in-system neutron spectrometry due to the following reactions: 31 P(n,γ) 32 P, 32 S(n,p) 32 P and 35 Cl(n,α) 32 P. For the reasons of similarity with Li 2 CO 3 , NH 4 PH 2 O 2 , CH 3 SO 2 CH 3 and NH 4 Cl were selected for measurement of 32 P activity. (J.P.N.)

Pulse shape discrimination with scintillation detectors

International Nuclear Information System (INIS)

Winyard, R.A.

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

Performance of Water-Based Liquid Scintillator: An Independent Analysis

Directory of Open Access Journals (Sweden)

D. Beznosko

2014-01-01

Full Text Available The water-based liquid scintillator (WbLS is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cerenkov rings and scintillation light, as well as the total cost reduction compared to pure liquid scintillator (LS. The independent light yield measurement analysis for the light yield measurements using three different proton beam energies (210 MeV, 475 MeV, and 2000 MeV for water, two different WbLS formulations (0.4% and 0.99%, and pure LS conducted at Brookhaven National Laboratory, USA, is presented. The results show that a goal of ~100 optical photons/MeV, indicated by the simulation to be an optimal light yield for observing both the Cerenkov ring and the scintillation light from the proton decay in a large water detector, has been achieved.

Near-infrared scintillation of liquid argon

Energy Technology Data Exchange (ETDEWEB)

Alexander, T. [Fermilab; Escobar, C. O. [Campinas State U.; Lippincott, W. H. [Fermilab; Rubinov, P. [Fermilab

2016-03-03

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

A comparative study of 19-iodo cholesterol-125I 3-acetate and Na 125I in liquid scintillation measurements

International Nuclear Information System (INIS)

Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

1994-01-01

A comparative study of performance of 19-iodo cholesterol 1 25I 3-acetate and sodium iodide samples labeled with 125I is presented for liquid scintillation counting measurements. Quench effect, count rate stability and spectral evolution of samples have been followed for several weeks in Toluene, Hisafe II, Instagel, Dioxane-naphthalene and Toluene-alcohol scintillators. Organic samples have negligible quench effect in the interval of I concentration of 0-90 μg and inorganic samples only show a very small variation, lower than 12%, for Dioxane-naphthalene, in the same range of concentration. Satisfactory stability is obtained in general for both, organic and inorganic samples, but small counting losses, 0.03% for 19-iodocholesterol 1 I 3-acetate samples in Tolue ne-alcohol and 0 .04% for Na 125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs

Preparation of ferric acetylacetonate, bonzonate and caprate labelled with Fe-55 and tests of application to liquid scintillation measurements

International Nuclear Information System (INIS)

Los Arcos, J.M.; Rodriguez Barquero, L.; Grau Malonda, A.

1990-01-01

The methods of preparation of ferric acetylacetonate, benzoate and caprate labelled with 55 Fe are described. The quenching effect, the spectral baehaviour and the count rate stability are studied by liquid scintillation measurements in toluene, INSTAGEL and HISAFE II, for two different values of the sample concentration. The ferric acetylaceton-ate is stable for all the three scintillators but shows a strong quench, while the ferric benzoate and caprate are stable only for INSTAGEL and HISAFE II showing no significant quench at the concentrat-ions of interest in habitual measurements. (Author)

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

International Nuclear Information System (INIS)

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

2017-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Zheng, Zhanlong [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Zhu, Jiayi [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Luo, Xuan, E-mail: luox76@gmail.com [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Xu, Yewei [School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Zhang, Qianfeng [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Zhang, Xing [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Bi, Yutie, E-mail: biyutie@sina.com [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Zhang, Lin [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China)

2017-04-01

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

{sup 226}Ra, {sup 228}Ra and {sup 210}Pb determination in surface water and groundwater by liquid scintillation counting

Energy Technology Data Exchange (ETDEWEB)

Faria, Ligia S.; Moreira, Rubens M., E-mail: ligsfaria@gmail.com, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2015-07-01

The municipalities of Brumadinho and Nova Lima are located in the metropolitan region of Belo Horizonte city, in the State of Minas Gerais. These two sites are important due to being located inside an Environmental Protection Area inserted in the Iron Quadrangle. In addition to the mineral wealth, the region has geological features that include quartz conglomerates associated with uranium and a significant groundwater potential exhibiting quite peculiar and complex hydrogeological features, such as the quartzite aquifer itself. Nuclear techniques applied to hydrology, such as Liquid Scintillation Counting technique (LSC), make possible the evaluation of natural radioactivity in surface water and groundwater. The objectives of this study were the determination of the activities of the long half-life radionuclides of the uranium and thorium series, such as {sup 226}Ra, {sup 228}Ra and {sup 210}Pb, and provide an effective methodology to define if the direct consumption of these waters can cause risk to health due to its radioactivity. The results were compared with the recommendations of the Ministry of Health. (author)

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

International Nuclear Information System (INIS)

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

2001-01-01

We present the concept and design of a liquid scintillator detector for a long-baseline neutrino oscillation experiment. Neutrinos interact in 2.5 cm thick steel plates alternating with 2.0 cm thick planes of liquid scintillator. The scintillator is contained in multicell PVC extrusions containing individual 2 cmx3 cm cells up to 8 m long. Readout of the scintillation light is via wavelength-shifting fibers which transport light to pixellated photodetectors at one end of the cells

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Evaluation of biodegradable and nonbiodegradable liquid scintillation cocktails used for tritium-in-water and urine analyses

International Nuclear Information System (INIS)

Haddock, J.A.

1992-11-01

The performance of a number of liquid scintillation cocktails was evaluated for quench resistance, sample capacity, cost, waste reduction and limit of detection. Directed towards the specific applications of counting tritium in water and urine samples, this study illustrated the potential of the newer, biodegradable cocktails, which mostly exhibited comparable or superior counting performance to the traditional cocktails. Reduced cocktail volumes and the use of mini vials is recommended for medium-load cocktails used for routine urine or water analyses, since a significant decrease in the volume of waste generated in Canadian nuclear facilities would result. (Author) (13 refs., 5 tabs., 44 figs.)

Standardization of method to determine 241Pu in urine samples by liquid scintillation analyzer

International Nuclear Information System (INIS)

Raveendran, Nanda; Rao, D.D.; Yadav, J.R.; Baburajan, A.

2015-01-01

As a part of radiation protection programme, occupational workers of fuel reprocessing plant are checked for internal contamination by analyzing urine samples periodically. Urine samples are analyzed to determine 239+240 Pu and 238 Pu by using standard conventional method and are counted by alpha spectrometry. 241 Pu is also one of the contaminant present in the urine sample of radiation workers. It is a low beta emitter with E max 21 keV. A methodology for the determination of this nuclide was standardized by using radiochemical analysis followed by Liquid Scintillation Counting. The method was tested and found suitable for the determination of 241 Pu in urine sample for the assessment of Committed Effective Dose (CED). (author)

Temperature quenching in LAB based liquid scintillator

Energy Technology Data Exchange (ETDEWEB)

Soerensen, A.; Zuber, K. [Technische Universitaet Dresden, Institute for Nuclear- and Particle Physics, Dresden (Germany); Hans, S.; Yeh, M. [Brookhaven National Laboratory, Chemistry Devision, Upton, NY (United States); Junghans, A.R.; Koegler, T.; Wagner, A. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Krosigk, B. v. [Technische Universitaet Dresden, Institute for Nuclear- and Particle Physics, Dresden (Germany); University of British Columbia, Department of Physics and Astronomy, Vancouver, BC (Canada); Lozza, V. [Technische Universitaet Dresden, Institute for Nuclear- and Particle Physics, Dresden (Germany); Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Lisboa (Portugal)

2018-01-15

The effect of temperature changes on the light output of LAB based liquid scintillator is investigated in a range from -5 to 30 C with α-particles and electrons in a small scale setup. Two PMTs observe the scintillator liquid inside a cylindrically shaped aluminum cuvette that is heated or cooled and the temperature dependent PMT sensitivity is monitored and corrected. The α-emitting isotopes in dissolved radon gas and in natural Samarium (bound to a LAB solution) excite the liquid scintillator mixtures and changes in light output with temperature variation are observed by fitting light output spectra. Furthermore, also changes in light output by compton electrons, which are generated from external calibration γ-ray sources, is analysed with varying temperature. Assuming a linear behaviour, a combined negative temperature coefficient of (-0.29 ± 0.01)%/ C is found. Considering hints for a particle type dependency, electrons show (-0.17 ± 0.02)%/ C, whereas the temperature dependency seems stronger for α-particles, with (-0.35 ± 0.03)%/ C. Due to a high sampling rate, a pulse shape analysis can be performed and shows an enhanced slow decay component at lower temperatures, pointing to reduced non-radiative triplet state de-excitations. (orig.)

A comparison between the measurements of Kr-85 in environmental samples by liquid scintillation and proportional counters; Comparacion de resultados de la medida radiactiva del Kr-85 ambiental por centelleo liquido y contadores proporcionales

Energy Technology Data Exchange (ETDEWEB)

Heras, M. C.; Perez, M. M.

1983-07-01

The most used methods for the measurement of Kr-81 beta-activity after their concentration and aisolation are the liquid scintillation counting and the proportional counter. In this work the beta activity of concentrated and aisolated Kr-85 samples measured in collaboration with the Max-Planck Institut fur Kernphyslk, Aussenstelle Freiburg. Samples taken both In Madrid and Frelburg are measured by proportional counters in the Max-Planck lnstitut, Freibury and by liquid scintillation counting in JEN, Madrid. The comparison of both measurements do not show appreciable discrepancy between the results obtained to both techniques. (Author)

Direct photon-counting scintillation detector readout using an SSPM

International Nuclear Information System (INIS)

Stapels, Christopher J.; Squillante, Michael R.; Lawrence, William G.; Augustine, Frank L.; Christian, James F.

2007-01-01

Gamma-ray detector technologies, capable of providing adequate energy information, use photomultiplier tubes (PMTs) or silicon avalanche photodiodes to detect the light pulse from a scintillation crystal. A new approach to detect the light from scintillation materials is to use an array of small photon counting detectors, or a 'detector-on-a-chip' based on a novel 'Solid-state Photomultiplier' (SSPM) concept. A CMOS SSPM coupled to a scintillation crystal uses an array of CMOS Geiger photodiode (GPD) pixels to collect light and produce a signal proportional to the energy of the radiation. Each pixel acts as a binary photon detector, but the summed output is an analog representation of the total photon intensity. We have successfully fabricated arrays of GPD pixels in a CMOS environment, which makes possible the production of miniaturized arrays integrated with the detector electronics in a small silicon chip. This detector technology allows for a substantial cost reduction while preserving the energy resolution needed for radiological measurements. In this work, we compare designs for the SSPM detector. One pixel design achieves maximum detection efficiency (DE) for 632-nm photons approaching 30% with a room temperature dark count rate (DCR) of less than 1 kHz for a 30-μm-diameter pixel. We characterize after pulsing and optical cross talk and discuss their effects on the performance of the SSPM. For 30-μm diameter, passively quenched CMOS GPD pixels, modeling suggests that a pixel spacing of approximately 90 μm optimizes the SSPM performance with respect to DE and cross talk

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

International Nuclear Information System (INIS)

Xiao Hualin; Wang Naiyan; Li Xiaobo; Cao Jun; Wen Liangjian; Zheng Dong

2010-01-01

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

COOLC, Ne-213 Liquid Scintillation Detector Neutron Spectra Unfolding

International Nuclear Information System (INIS)

1971-01-01

1 - Nature of physical problem solved: COOLC is designed to calculate a neutron energy spectrum from a pulse-height spectrum produced by a detector system using the liquid scintillator NE-213. 2 - Method of solution: The program estimates the counts which would be observed in an ideal detector system having a response which is specified by the user. The solution implicitly takes into account the non-negativity of the desired neutron spectrum. The solution is obtained by finding a nearly optimal combination of slices through the spectrometer response functions such that their sum approximates the response of a channel of the ideal analyzer, and then uses the coefficients so determined to obtain an estimate of the desired neutron spectrum. 3 - Restrictions on the complexity of the problem: There are none noted

Alpha liquid-scintillation spectrometry used for the measurement of uranium/thorium-disequilibria in soil samples

International Nuclear Information System (INIS)

Fueeg, B.; Tschachtli, T.; Kraehenbuehl, U.

1997-01-01

For the measurements of low-level radioactivity of natural samples. It is of interest to have a system with high counting efficiency. Alpha liquid-scintillation spectrometry is attractive, because it offers a 4 π geometry. Some chemical separation can be obtained using extractive scintillators. Due to quenching problems for natural samples, additional separation power is needed. A new sample preparation method was developed employing extraction chromatographic resin for measuring 238 U, 234 U, 232 Th, 230 Th, 228 Th and 226 Ra in soil samples, without using any uranium- or thorium-tracer for determining the chemical yields. This method was tested by analyzing the two different reference materials, IAEA-375, soil from Tschernobyl, as well as IAEA SDA-1, a deep-sea sediment with a high calcium content. For all analyzed radionuclides the recoveries were better than 90% with errors (confidence level of 95%) smaller than 5%. The minimal detectable concentration ranges between 0.2 and 0.8 Bq/kg, based on a one gram aliquot of sample and 80'000 seconds counting time. (orig.)

Internal Dosimetry Of I-131 For Radiation Workers Based On Analysis Of The Human Urine And Liquid Scintillation Counting

International Nuclear Information System (INIS)

Nguyen Van Hung; Pham Hung Thai; Le Van Ngoc

2011-01-01

Internal dosimetry of I-131 for radiation workers based on analysis of the human urine, measuring radioactivity by the liquid scintillation system, and dose calculation by the specialized code has been firstly studied at the Nuclear Research Institute. Urine samples from the subjects internally contaminated with I-131 through respiratory ways were collected, chemically processed, measured beta radioactivities of I-131 by the liquid scintillation system of ALOKA-LSC-6100, and then thyroid doses and effective ones for whole-body were calculated by using the specialized code of LUDEP 2.0. Based on chemically separation procedure for I-131 in urine samples and the low background HPGe gamma spectrometer of Canberra for measuring radioactivity, efficiency for chemical separation was determined to be (86.1 ± 5.0)%. The experimental results for 9 subjects with urine samples to be collected during 4 operating courses of Dalat nuclear reactor with production of I-131 (from June to September, 2010) were shown that thyroid doses and effective ones for whole-body for each course of I-131 production were in ranges of from 0.11 to 13.00 mSv and from 0.01 to 0.71 mSv, respectively. Therefore, totally average doses per year for thyroid and whole-body were less than the correlative levels of permissible doses. Besides, the liquid scintillation method was also compared experimentally with the gamma spectrometry (measuring directly urine samples by the gamma spectrometer to be carried out at the Institute before) was shown that errors on dosimetric results between them were less than 12%. This was proved the dosimetry has had a confidence, and it could be applied for internal dosimetry for radiation workers contacting with unsealed sources of I-131 in radiation installations as well as for diagnostic and therapeutic patients in health ones. (author)

Performance of two liquids scintillation and optimization of a Wallac 1411 counter in the tritium quantification in aqueous samples; Desempeno de dos centelleadores liquidos y optimizacion de un contador Wallac 1411 en la cuantificacion de tritio en muestras acuosas

Energy Technology Data Exchange (ETDEWEB)

Contreras de la Cruz, E. de J.; Lopez del Rio, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2014-10-15

The optimization of a liquid scintillation counting Wallac 1411 is presented as well as the performance of the liquids scintillation miscible in water OptiPhase Hi Safe 3 and Last Gold Ab, in the tritium quantification in aqueous samples. The luminescence effect, the quenching, the solution ph and the level of pulse amplitude comparator (Pac) were evaluated in the response of both liquids scintillation in the tritium measurement. The quenching and the luminescence modify the scintillators response; in the first of them the counting efficiency decreases and the minimum detectable activity increases; the second interferes in the tritium quantification in the interest window, but the effect disappears after 4 hours of darkness of the samples. The maximum counting efficiency was of 24% for OptiPhase Hi Safe 3 and 31% for Last Gold Ab, diminishing with the quenching until values of 8 and 11%, respectively. For a counting time of 6 hours and lower quenching, the minimum detectable concentration for OptiPhase Hi Safe 3 was of 13.4 ± 0.2 Bq/L and 9.9 ± 0.1 Bq/L for Last Gold Ab. Both scintillators responded appropriately to sour and basic solutions, being only presented chemiluminescence in Last Gold Ab to ph highly basic. The Pac application that varies between 1 and 256 does not have effect in the tritium measurement until values above 90. (Author)

Automatic quench compensation for liquid scintillation counting system

International Nuclear Information System (INIS)

Nather, R.E.

1978-01-01

A method of automatic quench compensation is provided, where a reference measure of quench is taken on a sample prior to taking a sample count. The measure of quench is then compared with a reference voltage source which has been established to vary in proportion to the variation of the measure of quench with the level of a system parameter required to restore at least one isotope spectral energy endpoint substantially to a selected counting window discriminator level in order to determine the amount of adjustment of the system parameter required to restore the endpoint. This is followed by the appropriate adjustment of the system parameter required to restore the relative position of the discriminator windows and the sample spectrum and is followed in turn by taking a sample count

Preparation and calibration by liquid scintillation of a sample of Cl 36. Preparacion y calibracion por centelleo liquido de una muestra de Cl 36

Energy Technology Data Exchange (ETDEWEB)

Grau Malonda, A; Los Arcos, J M; Rodriguez Barquero, L; Suarez, C [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain)

1989-01-01

A procedure to prepare a sample of Clorine 36, as Li{sup 36}Cl, able to be measured by liquid scintillation counting, is described. The sample is chemically stable, with no variation of the quenching parameter up to 4 mg of LiCl per 15 ml of scintillator, keeps constant the counting efficiency for concentration higher than 40 {mu}g of Li{sup 36}Cl in that volume, and shows no deterioration over a 3 weed period. The Li{sup 36}Cl solution has been standarized using the free parameter method with different volumes of toluene, PCS and Instagel, to an uncertainty of 0,3% (Author).

Survey on the presence of 90Sr in milk samples by a validated ultra low level liquid scintillation counting (LSC method

Directory of Open Access Journals (Sweden)

dell’Oro D.

2013-04-01

Full Text Available 90Sr is one of the most biologically hazardous radionuclides produced in nuclear fission processes and decays emitting high-energy beta particles turning 90Y. 90Sr is transferred from soil-plant to cow’s milk and then to humans if it is introduced into the environment. Radiostrontium is chemically similar to calcium entering the human body through several food chains and depositing in bone and blood-forming tissue (bone marrow. Among main foodstuffs assumed in human diet, milk is considered of special interest for radiostrontium determination, especially in emergency situations, because the consumption of contaminated milk is the main source of internal radiation exposure, particularly for infants. In this work an analytical method for the determination of radiostrontium in milk was developed and validated in order to determine low activity levels by liquid scintillation counting (LSC after achieving 90Y secular equilibrium condition. The analytical procedure was applied both in surveillance and routine programmes to detect radiocontamination in cow’s, goat and sheep milk samples.

Liquid scintillator for 2D dosimetry for high-energy photon beams

International Nuclear Information System (INIS)

Poenisch, Falk; Archambault, Louis; Briere, Tina Marie; Sahoo, Narayan; Mohan, Radhe; Beddar, Sam; Gillin, Michael T.

2009-01-01

Complex radiation therapy techniques require dosimetric verification of treatment planning and delivery. The authors investigated a liquid scintillator (LS) system for application for real-time high-energy photon beam dosimetry. The system was comprised of a transparent acrylic tank filled with liquid scintillating material, an opaque outer tank, and a CCD camera. A series of images was acquired when the tank with liquid scintillator was irradiated with a 6 MV photon beam, and the light data measured with the CCD camera were filtered to correct for scattering of the optical light inside the liquid scintillator. Depth-dose and lateral profiles as well as two-dimensional (2D) dose distributions were found to agree with results from the treatment planning system. Further, the corrected light output was found to be linear with dose, dose rate independent, and is robust for single or multiple acquisitions. The short time needed for image acquisition and processing could make this system ideal for fast verification of the beam characteristics of the treatment machine. This new detector system shows a potential usefulness of the LS for 2D QA.

Liquid scintillator for 2D dosimetry for high-energy photon beams

Energy Technology Data Exchange (ETDEWEB)

Poenisch, Falk; Archambault, Louis; Briere, Tina Marie; Sahoo, Narayan; Mohan, Radhe; Beddar, Sam; Gillin, Michael T. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard., Unit 94, Houston, Texas 77030 (United States)

2009-05-15

Complex radiation therapy techniques require dosimetric verification of treatment planning and delivery. The authors investigated a liquid scintillator (LS) system for application for real-time high-energy photon beam dosimetry. The system was comprised of a transparent acrylic tank filled with liquid scintillating material, an opaque outer tank, and a CCD camera. A series of images was acquired when the tank with liquid scintillator was irradiated with a 6 MV photon beam, and the light data measured with the CCD camera were filtered to correct for scattering of the optical light inside the liquid scintillator. Depth-dose and lateral profiles as well as two-dimensional (2D) dose distributions were found to agree with results from the treatment planning system. Further, the corrected light output was found to be linear with dose, dose rate independent, and is robust for single or multiple acquisitions. The short time needed for image acquisition and processing could make this system ideal for fast verification of the beam characteristics of the treatment machine. This new detector system shows a potential usefulness of the LS for 2D QA.

Simultaneous determination of environmental α-radionuclides using liquid scintillation counting combined with time interval analysis (TIA) and pulse shape discrimination (PSD)

International Nuclear Information System (INIS)

Hashimoto, T.; Sato, K.; Yoneyama, Y.; Fukuyama, N.

1997-01-01

Some improvements of the detection sensitivity in pulse time interval analysis (TIA) based on selective extraction of successively α-α correlated decay events within millisecond order from random or background events, were established by the utilization of PSD, to reject β/γ-pulses from α-ones and a simple chemical procedure of radium separation, together with the use of well resolved scintillator. By applying the PSD, the contribution of β-decay events was completely eliminated in both the α-spectra and the TIA distribution curves as well as the improvement into clear energy resolution and the enhancement of detection sensitivity for the TIA. As a result, the TIA and α-spectrometric analysis of 226 Ra-extract showed the existence of 223 Ra (Ac-series) and β/α-correlated events with correlated life (due to 0.16 ms due to 214 Bi(β)-> 214 Po(α)->) along with a singly well resolved α-peak to be useful for the determination of 226 Ra (U-series). The difference of half-lives (145 and 1.78 ms) due to 216 Po and 215 Po (direct daughters of 224 Ra for Th-series and 223 Ra for Ac-series, respectively) was also proven for the possibility of the simultaneous determination of both correlated events by using the TIA/PSD combined with chemical separation and liquid scintillation counting method. Finally, the simultaneous determination of three natural decay series, which include U-, Th- and Ac-series nuclides, have been conveniently carried out for some environmental samples using the present method combined with 225 Ra yield tracer (Np-series). (author)

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

International Nuclear Information System (INIS)

Li Xiaobo; Xiao Hualin; Cao Jun; Li Jin; Heng Yuekun; Ruan Xichao

2011-01-01

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

Scintillation proximity assay

International Nuclear Information System (INIS)

Hart, H.

1980-01-01

In a method of immunological assay two different classes of particles which interact at short distances to produce characteristic detectable signals are employed in a modification of the usual latex fixation test. In one embodiment an aqueous suspension of antigen coated tritiated latex particles (LH) and antigen coated polystyrene scintillant particles (L*) is employed to assay antibody in the aqueous medium. The amount of (LH) (L*) dimer formation and higher order aggregation induced and therefore the concentration of antibody (or antigen) present which caused the aggregation can be determined by using standard liquid scintillation counting equipment. (author)

Processing of liquid scintillation nuclear spectra for unquenched and quenched sources

International Nuclear Information System (INIS)

Madan, V.K.; Gopalakrishnan, K.R.

1997-01-01

This paper describes a nuclear (beta) spectral analysis method for qualitative and quantitative analysis of radioactivity for use in a liquid scintillation counting system. It is based on computing a spectral index number (SIN) for qualitative analysis of an unquenched sample. For quantitative analysis it was proposed that a complementary nonlinear function be estimated between efficiency and SIN from a standard set of samples. It reduces the computational burden. An unknown sample is analyzed by computing its SIN and that is used to calculate efficiency using the function to facilitate quantitative analysis. A software was developed and verified on real spectra of radioisotopes. The paper presents the method and its application with results. (author). 5 refs

Quenching measurements and modeling of a boron-loaded organic liquid scintillator

Energy Technology Data Exchange (ETDEWEB)

Westerdale, S.; Xu, J.; Shields, E.; Froborg, F.; Calaprice, F.; Alexander, T.; Aprahamian, A.; Back, H. O.; Casarella, C.; Fang, X.; Gupta, Y. K.; Lamere, E.; Liu, Q.; Lyons, S.; Smith, M.; Tan, W.

2017-08-01

Organic liquid scintillators are used in a wide variety of applications in experimental nuclear and particle physics. Boron-loaded scintillators are particularly useful for detecting neutron captures, due to the high thermal neutron capture cross section of $^{10}$B. These scintillators are commonly used in neutron detectors, including the DarkSide-50 neutron veto, where the neutron may produce a signal when it scatters off protons in the scintillator or when it captures on $^{10}$B. Reconstructing the energy of these recoils is complicated by scintillation quenching. Understanding how nuclear recoils are quenched in these scintillators is an important and difficult problem. In this article, we present a set of measurements of neutron-induced proton recoils in a boron-loaded organic liquid scintillator at recoil energies ranging from 57--467 keV, and we compare these measurements to predictions from different quenching models. We find that a modified Birks' model whose denominator is quadratic in $dE/dx$ best describes the measurements, with $\\chi^2$/NDF$=1.6$. This result will help model nuclear recoil scintillation in similar detectors and can be used to improve their neutron tagging efficiency.

Quenching measurements and modeling of a boron-loaded organic liquid scintillator

International Nuclear Information System (INIS)

Westerdale, S.; Xu, J.; Shields, E.; Froborg, F.; Calaprice, F.; Alexander, T.; Back, H.O.; Aprahamian, A.; Casarella, C.; Fang, X.; Gupta, Y.K.; Lamere, E.; Liu, Q.; Lyons, S.; Smith, M.; Tan, W.

2017-01-01

Organic liquid scintillators are used in a wide variety of applications in experimental nuclear and particle physics. Boron-loaded scintillators are particularly useful for detecting neutron captures, due to the high thermal neutron capture cross section of 10 B. These scintillators are commonly used in neutron detectors, including the DarkSide-50 neutron veto, where the neutron may produce a signal when it scatters off protons in the scintillator or when it captures on 10 B. Reconstructing the energy of these recoils is complicated by scintillation quenching. Understanding how nuclear recoils are quenched in these scintillators is an important and difficult problem. In this article, we present a set of measurements of neutron-induced proton recoils in a boron-loaded organic liquid scintillator at recoil energies ranging from 57–467 keV, and we compare these measurements to predictions from different quenching models. We find that a modified Birks' model whose denominator is quadratic in dE / dx best describes the measurements, with χ 2 /NDF=1.6. This result will help model nuclear recoil scintillation in similar detectors and can be used to improve their neutron tagging efficiency.

Ultra Low Level Tritium Analysis Method Using a Liquid Scintillation Counter

Energy Technology Data Exchange (ETDEWEB)

Noh, S. J.; Kim, H. J.; Kim, H.; Lim, H. J.; Lee, M. W.; Jeong, D. H.; Kim, J. K.; Kang, Y. R. [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Nam, S. H. [Inje University, Gimhae, (Korea, Republic of)

2015-05-15

To evaluate {sup 3}H concentration in the atmosphere more accurately compared to the conventional methods, the author of this paper intended to suggest more improved analytical methods and derived the elements which might occur during analysis or required improvements. The method suggested in this study is able to reduce the uncertainty and errors which may be existent in evaluating the {sup 3}H concentration of environmental sample s and thus will serve as the best solution in the technical and economic point of view. Liquid Scintillation Counter is the most widely used to analyze ultra-low level {sup 3}H by using CPM / DPM Counting Mode using external radiation source and Spectrum Plot Mode using internal radiation source. In CPM / DPM Counting Mode, multiple samples can be measured by single calibration despite its rather higher background whereas Spectrum Plot Mode requires more time and cost to analyze multiple samples despite its reliability to reduce the contribution of other radionuclides.

Low level scintillation counting of 239Pu

International Nuclear Information System (INIS)

Fueloep, M.; Minarik, F.; Cierna, V.

1984-01-01

For measuring the content of 239 Pu in samples taken from the working or living environment, methods should be used which are sufficiently sensitive for determining activities of the order of 10 -3 Bq. It is useful to use liquid scintillators for reasons of their 4π geometry and the exclusion of kinetic energy losses of particles detected in the sample and on the path between the sample and the detector. The method of background discrimination according to pulse shape may be used to suppress gamma background in the area of alpha particle peaks to the level 2.5x10 -4 s -1 . The diagram is given of electronic circuits for shape discrimination. The scintillator used was a SLS-31 with a PBD activator, a POPOP spectrum shifter and a mixture of solvents: toluene, dioxane and methanol. The efficiency of 239 Pu alpha particle detection is estimated at 78% and may further be improved by improving shape discrimination. (M.D.)

Optimization of cocktail volume in estimation of Tritium activity using liquid scintillation spectrometer

International Nuclear Information System (INIS)

Kumaravel, S.; Narashimha Nath, V.; Prashanth Kumar, M.; Sunil, C.N.; Raghunath, T.; Bera, Utpal; Ramakrishna, V.; Nair, B.S.K.; Ganesh, G.; Tripathi, R.M.

2016-01-01

Liquid Scintillation Spectrometers (LSS) are widely used for the estimation of Tritium in Nuclear Industry and Environmental labs to find out the Tritium concentration. The main component used for the detection of tritium is the liquid scintillation cocktail composed of different chemicals. To reduce the radioactive chemical wastes and the cost of liquid scintillation cocktails the use of as small volume of cocktail as possible is required. Typically, 1 ml of the aqueous sample is added with 5 ml of the liquid scintillation cocktail in a 20 ml low potassium glass. In this study, suitability of the combination of I ml aqueous sample with 2.5 ml cocktail in a 7 ml low potassium glass vial using a HIDEX 300 SL TDCR LSS was carried out instead of the other combination

A Monte-Carlo code for neutron efficiency calculations for large volume Gd-loaded liquid scintillation detectors

Energy Technology Data Exchange (ETDEWEB)

Trzcinski, A.; Zwieglinski, B. [Soltan Inst. for Nuclear Studies, Warsaw (Poland); Lynen, U. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Pochodzalla, J. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

1998-10-01

This paper reports on a Monte-Carlo program, MSX, developed to evaluate the performance of large-volume, Gd-loaded liquid scintillation detectors used in neutron multiplicity measurements. The results of simulations are presented for the detector intended to count neutrons emitted by the excited target residue in coincidence with the charged products of the projectile fragmentation following relativistic heavy-ion collisions. The latter products could be detected with the ALADIN magnetic spectrometer at GSI-Darmstadt. (orig.) 61 refs.

Data transfer from Beckman LS 5800 liquid scintillation counters to IBM personal computers.

Science.gov (United States)

Maan, A C

1985-09-01

This communication describes a short routine in BASICA for the IBM-PC, written to collect data from a Beckman liquid scintillation counter. In the form presented here the routine converts incoming bytes into separate lines and saves these lines in a file. There are many possible applications for further use of the data in these files. A few suggestions are given as to the format in which data can be stored and how to process these data automatically after all samples have been counted. The only hardware needed is an asynchronous communications adapter for the IBM-PC and an RS232 cable.

LET dependence of scintillation yields in liquid argon

Energy Technology Data Exchange (ETDEWEB)

Doke, Tadayoshi; Hitachi, Akira; Kikuchi, Jun; Crawford, H J; Lindstrom, P J; Masuda, Kimiaki; Shibamura, Eido; Takahashi, Tan

1988-06-01

Scintillation yields (scintillation intensity per unit absorbed energy) in liquid argon for ionizing particles are reviewed as a function of LET for the particles. The maximum scintillation yield, which is obtained for relativistic heavy ions from Ne to La, is about 1.2 times larger than that for gamma rays in NaI(Tl) crystal. In the low LET region, the scintillation yields for relativistic electrons, protons and He ions are 10-20% lower than the maximum yield. This tendency can be explained by taking into account the existence of the electrons which have escaped from their parent ions. In the high LET region, a quenching effect due to high ionization density is observed for alpha particles, fission fragments and relativistic Au ions.

Mass counting of radioactivity samples

International Nuclear Information System (INIS)

Oesterlin, D.L.; Obrycki, R.F.

1977-01-01

A method and apparatus for concurrently counting a plurality of radioactive samples is claimed. The position sensitive circuitry of a scintillation camera is employed to sort electrical pulses resulting from scintillations according to the geometrical locations of scintillations causing those pulses. A scintillation means, in the form of a scintillating crystal material or a liquid scintillator, is positioned proximate to an array of radioactive samples. Improvement in the accuracy of pulse classification may be obtained by employing collimating means. If a plurality of scintillation crystals are employed to measure the iodine-125 content of samples, a method and means are provided for correcting for variations in crystal light transmission properties, sample volume, and sample container radiation absorption. 2 claims, 7 drawing figures

High-resolution tracking using large capillary bundles filled with liquid scintillator

CERN Document Server

Annis, P; Benussi, L; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Van Dantzig, R; Dupraz, J P; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Feyt, J; Frekers, D; Frenkel, A; Galeazzi, F; Garufi, F; Goldberg, J; Golovkin, S V; Gorin, A M; Grégoire, G; Harrison, K; Höpfner, K; Holtz, K; Konijn, J; Kozarenko, E N; Kreslo, I E; Kushnirenko, A E; Liberti, B; Martellotti, G; Medvedkov, A M; Michel, L; Migliozzi, P; Mommaert, C; Mondardini, M R; Panman, J; Penso, G; Petukhov, Yu P; Rondeshagen, D; Siegmund, W P; Tyukov, V E; Van Beek, G; Vasilchenko, V G; Vilain, P; Visschers, J L; Wilquet, G; Winter, Klaus; Wolff, T; Wörtche, H J; Wong, H; Zimyn, K V

2000-01-01

We have developed large high-resolution tracking detectors based on glass capillaries filled with organic liquid scintillator of high refractive index. These liquid-core scintillating optical fibres act simultaneously as detectors of charged particles and as image guides. Track images projected onto the readout end of a capillary bundle are visualized by an optoelectronic chain consisting of a set of image-intensifier tubes followed by a photosensitive CCD or by an EBCCD camera. Two prototype detectors, each composed of \\hbox{$\\approx 10^6$} capillaries with \\hbox{20$-$25 $\\mu$m} diameter and \\hbox{0.9$-$1.8 m} length, have been tested, and a spatial resolution of the order of \\hbox{20$-$40 $\\mu$m} has been attained. A high scintillation efficiency and a large light-attenuation length, in excess of 3 m, was achieved through special purification of the liquid scintillator. Along the tracks of minimum-ionizing particles, the hit densities obtained were $\\sim$ 8 hits/mm at the readout window, and \\hbox{$\\sim$ 3 ...

Preparation of 45Ca(HDEHP)n and (CaH{sub 1}50{sub 2})2 samples for liquid scintillation counting, compared to 45caCl{sub 2} results; Preparacion de Ca (HDEHP)n y (C{sub 8}H{sub 1}50{sub 2})2 marcados con 45Ca y estudio comparativo con 4 5ca Cl2 en medidas por centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, L.; Arcos, J. M. los; Grau Malonda, A.

1994-07-01

A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethylhexanoate calcium salt, labelled with 45Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators,Toluene-alcohol, Dioxane-naphtalene, Hi safe II, Ultimate-Gold and Instagel, and compared to results obtained from a commercial solution of 4 5CaCl2. (Author) 7 refs.

Influence of atomic and nuclear constants on the counting efficiency for 55{sup F}e in liquid scintillators; Influencia de los parametros atomicos y nucleares en la calibracion de 55{sup F}e mediante centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Fernandez, A.; Grau, A.; Arcos, J. M. los

1985-07-01

In this paper one considers the influence of the different parameters on the determination of the uncertainty of the detection efficiency for 55{sup F}e when the counting technique of liquid scintillation is applied. The following parameters are considered: the relative probabilities of X and Auger emission so as their corresponding energies, the fluorescence yields W{sup K} and W{sup L}, and the non-interaction probabilities of the emitted X photons. (Author) 11 refs.

Study of the radioactivity of drinking water in the city of Antsirabe using the method of liquid scintillation counting

International Nuclear Information System (INIS)

RAKOTOMANGA, H.

2003-01-01

The objective of this work is to determine the radioactivity by liquid scintillation counting (LSC) and to study the distribution of radionuclides in drinking water from the Antsirabe region. Optiphase Hisafe 3TM is used to measure gross alpha-beta radioactivity. Radium, radon and the excess of short half-life radionuclides are obtained from MaxilightTM cocktail. Results of measurement of drinking water samples show that : gross alpha-beta activities are between (120±27) Bq.l -1 and (426±47) Bq.l -1 , the radium activities are from (14±2)Bq.l -1 to (78±5) Bq.l -1 , radon activities are from (0.6±0.2)Bq.l -1 to (60±6) Bq.l -1 , short half-life radionuclides activities are between 25±8 Bq.l -1 and 270±27 Bq.l -1 .Annual dose exposure from ingestion of radium-226 is between (2.09 ± 0.32)mSv and (11.03 ± 0.73)mSv. These values are close to the Malagasy standard (5 mSv). The results show that drinking waters from the Antsirabe region contain natural radionuclides. Dose exposure increases if the water is directly ingested after collection. [fr

Enhanced counting efficiency of Cerenkov radiation from bismuth-210

International Nuclear Information System (INIS)

Peck, G.A.; Smith, J.D.

1998-01-01

This paper describes the measurement of 210 Bi by Cerenkov counting in a commercial liquid scintillation counter. The counting efficiency in water is 0.17 counts per second per Becquerel (17%). When the enhancers Triton X-100 (15% v/v) and sodium salicylate (1% m/v) are added to the solution the counting efficiency for 210 Bi increases from 17% to 75%. The 210 Po daughter of 210 Bi causes interference of 0.85 counts per second per Becquerel in the presence of the enhancers but not in water. When 210 Bi and 210 Po are present in secular equilibrium the total counting efficiency is 160%. When 210 Bi and 210 Po are not in secular equilibrium the 210 Po can be removed immediately before counting by plating onto silver foil. The use of the enhancers gives a substantial increase in counting efficiency compared to counting in water. Compared with solutions used in liquid scintillation counting the enhancer solution is inexpensive and can be disposed of without environmental hazard. (author)

Measurement of wavelength-dependent refractive indices of liquid scintillation cocktails

International Nuclear Information System (INIS)

Kossert, Karsten

2013-01-01

Refractive indices of several commercial liquid scintillation cocktails were measured by means of an automatic critical-angle dispersion refractometer in the wavelength range from 404.7 nm to 706.5 nm. The results are needed for various applications. In particular, detailed Monte Carlo simulations of liquid scintillation counters that include the computation of optical light require these data. In addition, the refractive index is an important parameter for studies of micelle sizes by means of dynamic light scattering. In this work, the refractive indices were determined for Ultima Gold™, Ultima Gold™ F, Ultima Gold™ LLT, Ultima Gold™ AB, Hionic Fluor™, Permafluor ® E+, Mineral Oil Scintillator, Insta-Gel Plus, OptiPhase HiSafe 2, OptiPhase HiSafe 3, Ultima Gold™ XR, Insta-Gel Plus, AquaLight, MaxiLight and Ultima Gold™ MV at 16 °C, 18 °C, 20 °C and 22 °C. The carbon dioxide absorber Carbo-Sorb ® E was also analyzed. For some scintillators, various batches were compared and mixtures with water or nitromethane were studied. - Highlights: • Refractive indices of several liquid scintillation cocktails were measured. • The wavelengths cover a range from 404.7 nm to 706.5 nm. • Measurements were carried out at 16 °C, 18 °C, 20 °C and 22 °C. • For some cocktails, mixtures with water or nitromethane were studied

Development of a reference liquid scintillation cocktail

CSIR Research Space (South Africa)

Van Wyn Gaardt, WM

2006-02-01

Full Text Available A reference system that would allow national laboratories to compare their activity measurements of non-gamma-emitting radionuclides at any time is currently being developed. The system requires a non-commercial reference-liquid scintillation...

Composition for use in scintillator systems

International Nuclear Information System (INIS)

Tarkkanen, V.

1976-01-01

A liquid scintillation counting composition of the type comprising an aromatic hydrocarbon solvent, an ethoxylated alkyl phenol surfactant, and a scintillation solute, containing a small amount of a substituted ethoxylated carboxylate acid and/or a tertiary amine salt or a quaternary ammonium salt of such acid is described. The free acid reduces chemiluminescence upon the addition of an alkaline sample to the composition, while the tertiary amine or quaternary ammonium salt enhances the water miscibility of the composition

Detection of supernova neutrinos in the liquid-scintillator experiment LENA

International Nuclear Information System (INIS)

Winter, Jurgen Michael Albrecht

2014-01-01

The LENA project (Low-Energy Neutrino Astronomy) is a planned large-volume liquid-scintillator detector. The good energy resolution, low-energy threshold, and its large mass allow to perform real-time spectroscopy of low-energy neutrinos with high statistics. This is especially beneficial for the observation of rare events such as a galactic core-collapse supernova. In a liquid scintillator, interactions by different particle types cause different scintillation light pulse shapes. They can be used to identify proton recoils induced by neutrino-proton scattering from supernova neutrinos or by cosmogenic knock-out neutrons. In order to evaluate the performance of the detector, a precise characterization of the liquid scintillator is necessary. In the course of this work, an experiment has been set up at the Maier-Leibnitz-Laboratorium in Garching in order to determine the pulse shape of proton and electron recoils in different liquid-scintillator mixtures. Neutrons produced via 11 B(p,n) 11 C or an americiumberyllium source were used to induce proton recoils. Compton scattering of simultaneously emitted γs provided information on the electron recoils. A time-of-flight measurement allows for an easy identification of neutron and γ induced events and thus effective background reduction. The tail-to-total and the Gatti method are used in order to determine the energy-dependent discrimination power of proton and electron recoils in liquid scintillator. Combining both methods, a proton recoil identification efficiency of (99.70±0.05)% can be achieved between 1-1.5 MeV, while suppressing 99% of the γ induced recoils for the probable liquid scintillator mixture for LENA, linear alkylbenzene (LAB) as solvent and 3 g/l 2,5-diphenyloxazole (PPO) and 20mg/l 1,4-bis-(o-methylstyryl)-benzole (bisMSB) as fluors. Moreover, the decay constants τ i and the respective amplitudes n i are determined for various liquid scintillator mixtures. It can be observed that the decay times

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

Science.gov (United States)

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.

Scintillation trigger system of the liquid argon neutrino detector

International Nuclear Information System (INIS)

Belikov, S.V.; Gurzhiev, S.N.; Gutnikov, Yu.E.; Denisov, A.G.; Kochetkov, V.I.; Matveev, M.Yu.; Mel'nikov, E.A.; Usachev, A.P.

1994-01-01

This paper presents the organization of the Scintillation Trigger System (STS) for the Liquid Argon Neutrino Detector of the Tagged Neutrino Facility. STS is aimed at the effective registration of the needed neutrino interaction type and production of a fast trigger signal with high time resolution. The fast analysis system of analog signal from the trigger scintillation planes for rejection of the trigger signals from background processes is described. Real scintillation trigger planes characteristics obtained on the basis of the presented data acquisition system are shown. 10 refs., 12 figs., 3 tabs

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

International Nuclear Information System (INIS)

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

Optical properties of quantum-dot-doped liquid scintillators

International Nuclear Information System (INIS)

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

2013-01-01

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

SBIR Final Report. Liquid Core Optical Scintillating Fibers

International Nuclear Information System (INIS)

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

2000-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

Infrared scintillation: a comparison between gaseous and liquid xenon

International Nuclear Information System (INIS)

Bressi, G.; Carugno, G.; Conti, E.; Del Noce, C.; Iannuzzi, D.

2001-01-01

Light yield and spectrum of infrared (IR) scintillation in Xe are different in gaseous and liquid phases. In gas, the spectrum consists mainly of a broad line centered at 1300 nm. In liquid, light is emitted primarily below 1200 nm and with a lower yield

Determination of phosphorus-32 in wet-digested plant leaves by Cerenkov counting

International Nuclear Information System (INIS)

Wahid, P.A.; Kamalam, N.V.; Sankar, S.J.

1985-01-01

A method of determination of 32 P activity in leaf samples by Cerenkov counting technique is described. The method involves wet digestion of oven-dried leaves with 1:1 nitric-perchloric acid mixture followed by transferring the digest into a scintillation counting vial with distilled water upto a final volume of 20 mL, and determining the activity in a liquid scintillation system. Reproducible count rates can be obtained if the vials are counted after 4h allowing the silica in the digest to settle. (author)

Neutron spectrometer using NE218 liquid scintillator

International Nuclear Information System (INIS)

Dance, J.B.; Francois, P.E.

1976-01-01

A neutron spectrometer has been constructed using NE218 liquid scintillator. Discrimination against electron-gamma events was obtained usng a charge-comparison pulse shape discrimination system. The resolution obtained was about 0.25 MeV F.W.H.M. at 2.0 MeV

Comparison of plastic scintillating fibres and capillaries filled with liquid scintillator

International Nuclear Information System (INIS)

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

1994-01-01

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

The Use of Diethanolamine as a Co2 Absorbent in Was Take the Determination Coral Reef Age in Barrang Lompo Island Spermonde Islands Through Measurements of 14c Activity by Liquid Scintillation Counting (Lsc) Method

OpenAIRE

Matande, Jumiati Bunga; Zakir, Muhammad; Noor, Alfian

2017-01-01

Research on the use of diethanolamine (DEA) as a CO2 absorbent in was take the determination coral reef age in Barrang Lompo Island, Spermonde Islands through measurements of 14C activity by liquid scintillation Counting method (LSC) was carried our. Coral reef sample of the island Barrang Lompo at coordinates 5 ° 06 '49 " LS 119 ° 25' 20" BT with a dept of 3-4 meters from the sea surface. Coral reefs (coral reef) is an ecosystem that live on the water in the form of limestone formations (CaC...

Measuring fast neutrons with large liquid scintillation detector for ultra-low background experiments

Energy Technology Data Exchange (ETDEWEB)

Zhang, C. [Department of Physics, The University of South Dakota, Vermillion, SD 57069 (United States); College of Sciences, China Three Gorges University, Yichang 443002 (China); Mei, D.-M., E-mail: dongming.mei@usd.edu [Department of Physics, The University of South Dakota, Vermillion, SD 57069 (United States); Davis, P.; Woltman, B. [Department of Physics, The University of South Dakota, Vermillion, SD 57069 (United States); Gray, F. [Department of Physics and Computational Science, Regis University, Denver, CO 80221 (United States)

2013-11-21

We developed a 12-liter volume neutron detector filled with the liquid scintillator EJ301 that measures neutrons in an underground laboratory where dark matter and neutrino experiments are located. The detector target is a cylindrical volume coated on the inside with reflective paint (95% reflectivity) that significantly increases the detector's light collection. We demonstrate several calibration techniques using point sources and cosmic-ray muons for energies up to 20 MeV for this large liquid scintillation detector. Neutron–gamma separation using pulse shape discrimination with a few MeV neutrons to hundreds of MeV neutrons is shown for the first time using a large liquid scintillator.

Validation the quantification of beta emitters activity in urine by scintillation spectrometry in the liquid phase; Validacion de la cuantificacion de actividad de emisores beta en orina mediante espectrometria de centelleo en fase liquida

Energy Technology Data Exchange (ETDEWEB)

Sierra, I.; Hernandez, C.; Benito, P.; Lopez, C.

2013-07-01

In this paper the methodology used in the validation of the technique for quantifying activity of some beta emitters in urine ({sup 3}H, {sup 1}4C, {sup 3}5S, {sup 3}2P and {sup 9}0Sr) by scintillation spectrometry Liquid Phase (Liquid Scintillation Counting, LSC) is described in bio elimination Laboratory Service CIEMAT Radiation Dosimetry accredited since last year for carrying out assays measure radiation dose based on ISO forth above. (Author)

Background characterization in a liquid scintillation spectrometer; Caracterizacion del fondo de un espectrometro de centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Barquero, L.; Los Arcos, J.M.; Jimenez de Mingo, A.

1995-07-01

An alternate procedure for background count rate estimation in a liquid scintillation spectrometer is presented, which does not require to measure a blank with similar composition, volume and quench, to the problem sample. The procedure is based on a double linear parameterization which was obtained from a systematic study of the background observed with glass vials, in three different windows, 0 - 20 KeV, 0 - 800 KeV and 0 - 2 MeV, for volume between 2 and 20 mi of three commercial scintillators, Hisafe II, Ultima-Gold and Instagel, and quenching degree in the interval equivalent to 50% - 3% tritium efficiency. This procedure was tested with standard samples of 3H, and led to average discrepancies less than 10% for activity {>=}0,6 Bq, against conventional methods for which the discrepancies are twice on average. (Author) 10 refs.

Determination of thoron and radon ratio by liquid scintillation spectrometry

International Nuclear Information System (INIS)

Yoshikawa, H.; Nakanishi, T.; Nakahara, H.

2006-01-01

A portable liquid scintillation counter was applied for the analysis of alpha-ray energy spectrum to determine the ratio of 220 Rn/ 222 Rn in fumarolic gas in the field. A surface-polished vial was developed, by which a Gaussian distribution could be approximated for the alpha-ray energy spectra and the peak areas of the nuclides could be estimated independently, because of the wide FWHM in the liquid scintillation pulse. A fumarolic gas sample was collected in Mt. Kamiyama (Hakoneyama geothermal field in Japan) having low 220 Rn/ 222 Rn ratio of 2.20 ± 0.13. (author)

Advances in the sample preparation and the detector for a combined solvent extraction-liquid scintillation method of low-level plutonium measurement

International Nuclear Information System (INIS)

Perdue, P.T.; Christian, D.J.; Thorngate, J.H.; McDowell, W.J.; Case, G.N.

1976-07-01

A combined solvent extraction-liquid scintillation technique, developed at Oak Ridge National Laboratory (ORNL), has many possible applications to the determination of low levels of plutonium and other alpha-emitting nuclides. Using these procedures, plutonium can be extracted from biological or environmental samples and introduced directly into a liquid scintillator. Quenching of the scintillator is thus minimized so that spectroscopic techniques may be employed. Existing chemical procedures and counting equipment were reviewed and improved. Purification of the di(2-ethylhexyl)phosphoric acid (used as the actinide extractant) was found necessary. Destruction of organic material in the sample and control of the valence state of plutonium were found to be major sources of irreproducibility. Methods were developed to allow samples separated with commonly used ion exchange techniques to be extracted into the scintillator. Comparisons were made of a wide variety of the components and parameters of the detector system to find the best combination of pulse-height resolution and pulse-shape discrimination. When a single phototube was used, optimum performance was obtained using a hemispherical reflector-sample holder viewed sideways by an RCA 8575 photomultiplier tube used in conjunction with a special integrating preamplifier and a good quality linear amplifier that used delay lines to shape the pulses

Pulse-shape discrimination in NE213 liquid scintillator detectors

International Nuclear Information System (INIS)

Cavallaro, M.; Tropea, S.; Agodi, C.; Assié, M.; Azaiez, F.; Boiano, C.; Bondì, M.; Cappuzzello, F.; Carbone, D.; De Napoli, M.; Séréville, N. de; Foti, A.; Linares, R.; Nicolosi, D.; Scarpaci, J.A.

2013-01-01

The 16-channel fast stretcher BaFPro module, originally developed for processing signals of Barium Fluoride scintillators, has been modified to make a high performing analog pulse-shape analysis of signals from the NE213 liquid scintillators of the EDEN neutron detector array. The module produces two Gaussian signals, whose amplitudes are proportional to the height of the fast component of the output light and to the total energy deposited into the scintillator, respectively. An in-beam test has been performed at INFN-LNS (Italy) demonstrating a low detection threshold, a good pulse-shape discrimination even at low energies and a wide dynamic range for the measurement of the neutrons energy.

Liquid scintillator calorimetry for the LHC

International Nuclear Information System (INIS)

Artamonov, A.; Buontempo, S.; Epstein, V.; Ereditato, A.; Fiorillo, G.; Garufi, F.; Golovkin, S.; Gorbunov, P.; Jemanov, V.; Khovansky, V.; Kruchinin, S.; Maslennikov, A.; Medvedkov, A.; Vasilchenko, V.; Zaitsev, V.; Zuckerman, I.

1995-01-01

We report on the beam tests of full scale liquid scintillator modules designed for a very forward calorimeter for an experiment at the CERN Large Hadron Collider (LHC). Tests were performed in the electron beams of the SPS at CERN within the 20 and 150 GeV energy range. The response as a function of the beam impact point and incidence angle was measured. (orig.)

Measurement of light emission in scintillation vials

International Nuclear Information System (INIS)

Duran Ramiro, M. Teresa; Garcia-Torano, Eduardo

2005-01-01

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

Fast and sensitive determination of Sr-90 and SR-89 activity in milk by ion-chromatography and liquid scintillation

International Nuclear Information System (INIS)

Figueiredo, V.; Herrmann, A.

1992-01-01

A method for fast and exact determination of both strontium isotopes in milk and other foodstuffs, combination high performance ion chromatographic separation with by liquid scintillation counting, which enables the desired results to be obtained with very satisfactory precision and reproducibility within 24 hours, has been developed. The lowest detectable activity lies by 3 Bq/liter for Sr-90 and 1 Bq/liter for Sr-89 which is satisfactory for assessing a situation in a time crisis. (author)

Theory and application of Cerenkov counting

Energy Technology Data Exchange (ETDEWEB)

Ross, H.H.

1976-01-01

The production of Cherenkov radiation by charged particles moving through a transparent medium (the Cherenkov generator) is a strictly physical process that is virtually independent of the chemistry of the medium. Thus, it is possible to calculate easily all of the important parameters of the Cherenkov process such as excitation threshold, emission intensity, spectral distribution, directional characteristics, and time response. The results of many of these physical effects are unknown in conventional liquid scintillation spectroscopy and, therefore, many unique assay techniques have been developed as a result of their consideration. This paper discusses the theoretical basis of the Cherenkov process, explores the unusual characteristics of the phenomenon, and demonstrates how these unusual characteristics can be used to develop equally unusual counting methodologies. Particular emphasis is directed toward an analysis of published data (obtained with conventional liquid scintillation instrumentation) that would be difficult or impossible to obtain with other counting techniques. Also discussed is a new type of sample vial that uses an isolated waveshifting system. The device was specifically designed for Cherenkov counting.

Influence of dissolved gas and temperature on the light yield of new liquid scintillators

CERN Document Server

Buontempo, S; Golovkin, S V; Martellotti, G; Medvedkov, A M; Penso, G; Soloviev, A S; Vasilchenko, V G

1999-01-01

Sixteen new liquid scintillators, emitting green light, were studied. They are based on four solvents combined with four dopants. The influence of different gas atmospheres was studied. In particular it was shown that by keeping these liquid scintillators in vacuum or in a neutral gas, the light yield increases up to 32~\\% at 20 $^{\\circ}$C and for the best solvent-dopant combinations. The dependance of the light yield on temperature was also studied for these scintillators. In the 20--60 $^{\\circ}$C interval, some exhibit a light yield variation of $\\sim$ 3 \\% which is smaller than that of the NE 102A plastic scintillator.

Low-level liquid scitillation counting for quantification of annual {sup 3}H and {sup 14}C concentrations in tree disks

Energy Technology Data Exchange (ETDEWEB)

Kopka, B [Goettingen Univ. (Germany). Isotopenlaboratorium fuer Biologische und Medizinische Forschung; Schikowski, J [Goettingen Univ. (Germany). Isotopenlaboratorium fuer Biologische und Medizinische Forschung; Porstendoerfer, J [Goettingen Univ. (Germany). Isotopenlaboratorium fuer Biologische und Medizinische Forschung

1997-03-01

The government of Schleswig Holstein funded a study to perform the retrospective determination of airborne {sup 3}H and {sup 14}C concentrations. It is well known, that in tree rings most of the hydrogen and cabron is fixed after insertion in the matrix of wood and that the radionuclide concentration correlates with former airborne activity concentrations. For the retrospective study wood disks of trees located in the region near the nuclear power plant of Kruemmel and control disks of unsuspected areas were selected. The hydrogen of the wood was transformed to water and the carbon to carbondioxide by classical oxidation processes (combustion in a furnace). The contents of {sup 3}H in the water and {sup 14}C of the carbondioxide (solved in scintillation liquid) were determined by liquid scintillation counting, using a low-level counter (type Quantulus 1220, Wallac). (orig.)

Radiostrontium accumulation in animal bones: development of a radiochemical method by ultra low-level liquid scintillation counting for its quantification.

Science.gov (United States)

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

2018-03-31

Strontium-90 (90Sr) is a fission product, resulting from the use of uranium and plutonium in nuclear reactors and weapons. Consequently, it may be found in the environment as a consequence of nuclear fallouts, nuclear weapon testing, and not correct waste management. When present in the environment, strontium-90 may be taken into animal body by drinking water, eating food, or breathing air. The primary health effects are bone tumors and tumors of the blood-cell forming organs, due to beta particles emitted by both 90Sr and yttrium-90 (90Y). Moreover, another health concern is represented by inhibition of calcification and bone deformities in animals. Actually, radiometric methods for the determination of 90Sr in animal bones are lacking. This article describers a radiochemical method for the determination of 90Sr in animal bones, by ultra low-level liquid scintillation counting. The method precision and trueness have been demonstrated through validation tests (CV% = 12.4%; mean recovery = 98.4%). Detection limit and decision threshold corresponding to 8 and 3 mBecquerel (Bq) kg-1, respectively, represent another strong point of this analytical procedure. This new radiochemical method permits the selective extraction of 90Sr, without interferences, and it is suitable for radiocontamination surveillance programs, and it is also an improvement with respect to food safety controls.

Standardization of 137mCs+137mBa by Liquid Scintillation; Calibracion de 137Cs+137mBa por Centelleo Liquido

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, L.; Los Arcos, J.M.; Grau, A.

1995-07-01

A procedure for the preparation of a stable, homogeneous solution of 137Cs+''137mBa, for use in liquid scintillation measurements, is described. Its count rate stability and spectral time evolution has been followed for several weeks. The solution has been standardised by the CIEMAT/NIST method in both Ultima-Gold and Insta-Gel, to a combined uncertainty lower than 0,51 % (k=l). (Author) 5 refs.

Low energy neutrino astronomy with the large liquid-scintillation detector LENA

International Nuclear Information System (INIS)

Undagoitia, T Marrodan; Feilitzsch, F von; Goeger-Neff, M; Hochmuth, K A; Oberauer, L; Potzel, W; Wurm, M

2006-01-01

The detection of low energy neutrinos in a large liquid scintillation detector may provide further important information on astrophysical processes as supernova physics, solar physics and elementary particle physics as well as geophysics. In this contribution, a new project for Low Energy Neutrino Astronomy (LENA) consisting of a 50 kt scintillation detector is presented

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

Energy Technology Data Exchange (ETDEWEB)

Keefer, G., E-mail: gregkeefer@llnl.gov [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Grant, C. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Piepke, A. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa 277-8583 (Japan); Ebihara, T.; Ikeda, H. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Kishimoto, Y. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa 277-8583 (Japan); Kibe, Y.; Koseki, Y.; Ogawa, M.; Shirai, J.; Takeuchi, S. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Mauger, C.; Zhang, C. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Schweitzer, G. [Department of Chemistry, University of Tennessee, Knoxville, TN 37996 (United States); Berger, B.E. [Department of Physics, Colorado State University, Fort Collins, CO 80523 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa 277-8583 (Japan); Dazeley, S. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Decowski, M.P. [Physics Department, University of California, Berkeley, Berkeley, CA 94720 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa 277-8583 (Japan); Detwiler, J.A. [Physics Department, University of California, Berkeley, Berkeley, CA 94720 (United States); Djurcic, Z. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); and others

2015-01-01

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

Liquid scintillation vial for radiometric assay of lymphocyte carbohydrate metabolism in response to mitogens

International Nuclear Information System (INIS)

Tran, N.; Wagner, H.N. Jr.

1978-01-01

We have demonstrated that mitogens--i.e., PHA and Con.A--stimulate lymphocyte carbohydrate metabolism using a liquid-scintillation vial with conventional liquid-scintillation detectors. The results showed that this enclosed system can be useful for development of rapid in vitro tests of lymphocytes immune responsiveness, as well as for radiometric detection of bacterial growth in various gaseous atmospheres

Influence of temperature to quenching on liquid scintillation measurement

CERN Document Server

Kato, T

2003-01-01

The amount of quench is measured with liquid scintillation spectrometer changing the temperature of the sample. The range of the changed temperature is between 0 deg C and 35 deg C. The measurement is carried out for three kinds of unquenched standard, two quenched standards and fifteen kinds of scintillation cocktail and the mixed sample. It is confirmed that the amount of quench increases for all samples as the temperature rises. The influence of the changed amount of quench to the quench correction is examined. (author)

Liquid mixtures for scintillation counters

International Nuclear Information System (INIS)

Kauffmann, J.M.

1975-01-01

Liquid scintillators contain emulsifiers or combinations of these which can be used over a wide temperature range for a multitude of aqueous samples. These emulsifiers are block-polymerides with a nonhygroscopic center part of the chain of oxypropylene combinations recieved by addition of propylene oxide to both hydroxyl groups of a propylene-glycol nucleus and both ends of the center part of the chain terminating in hygroscopic poly(oxyethylene) groups. The length of the nonhygroscopic center part of the chain varies from about 800 to 3,000 or 4,000 in molecular weight. The hygroscopic poly(oxyethylene) end groups have a controlled length constituting about 10 to 80wt.% of the finished molecule. The most useful members of this group of co-polymerides possess a length of their poly(oxypropylene) chains corresponding to a value of y of about 15 to 56 and a length of their poly(oxyethylene)chains corresponding to values of x and z between 1 and 35 . All known fluorines can be used. With the scintillators the radioimmunoassay can also be carried through. (DG/PB) [de

Methyl salicylate as a medium for radioassay of 36Cl using a liquid scintillation spectrometer

International Nuclear Information System (INIS)

Wiebe, L.I.; Ediss, C.

1976-01-01

Methyl salicylate (MS), a high refractive index liquid with wave-shifting properties, has been used as a Cherenkov radiation generating medium for the radioassay of 36 Cl by liquid scintillation (LS) spectrometer. Comparative experiments, using both a standard toluene-based LS fluor and toluene alone, for the measurement of 36 Cl were undertaken. The methyl salicylate medium was found to perform at an intermediate counting efficiency, near that for the LS fluor. In the presence of moderate amounts of nitromethane, the MS was less susceptible to chemical quenching effects than either the fluor or toluene. Counting efficiencies for 36 Cl in MS, toluene and toluene fluor respectively were 82.4, 28.4 and 100.3 percent with a Picker Liquimat 220 LS spectrometer, and 91.6, 54.9 and 100.0 percent with a Searle Mark III LS spectrometer. The addition of nitromethane (11.3 percent of final volume) reduced these efficiencies to 50.5, 10.0 and 15.4 percent, and to 58.8, 12.4 and 19.0 percent, respectively. The data are discussed in relation to observed changes in the pulse height spectra. Chemical quench correction by ESCR and by SCR methods is reported

Primary standardization of {sup 152}Eu by 4πβ(LS) - γ (NaI) coincidence counting and CIEMAT-NIST method

Energy Technology Data Exchange (ETDEWEB)

Ruzzarin, A., E-mail: aruzzarin@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (LIN/PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentação Nuclear; Cruz, P.A.L. da; Ferreira Filho, A.L.; Iwahara, A. [Instituto de Radioproteção e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiações Ionizantes

2017-07-01

The 4πβ-γ coincidence counting and CIEMAT/NIST liquid scintillation method were used in the standardization of a solution of {sup 152}Eu. In CIEMAT/NIST method, measurements were performed in a Liquid Scintillation Counter model Wallac 1414. In the 4πβ-γ coincidence counting, the solution was standardized using a coincidence method with 'beta-efficiency extrapolation'. A simple 4πβ-γ coincidence system was used, with acrylic scintillation cell coupled to two coincident photomultipliers at 180° each other and NaI(Tl) detector. The activity concentrations obtained were 156.934 ± 0.722 and 157.403 ± 0.113 kBq/g, respectively, for CIEMAT/NIST and 4πβ-γ coincidence counting measurement methods. (author)

Wavelength shifting reflector foils for liquid Ar scintillation light

Energy Technology Data Exchange (ETDEWEB)

Walter, Manuel [Physik Institut, Universitaet Zuerich (Switzerland); Collaboration: GERDA-Collaboration

2013-07-01

Liquid argon is used as a scintillator in several present and upcoming experiments. In Gerda it is used as a coolant, shielding and will be instrumented to become an active veto in Phase II. Its scintillation light has a wavelength of 128 nm, that gets absorbed by quartz. In order to measure the light using photo multiplier tubes (PMT) for cryogenic temperatures which have a quartz window, it is converted to longer wavelength by coated reflector foils. The conversion efficiency and stability of several such coatings was optimized using VM2000 and Tetratex separately as reflector foils. The efficiency has been measured in a liquid Ar set up build especially for this purpose. It employs a 3'' low radioactivity PMT of type R11065-10 from Hamamatsu, the favorite photo sensor candidate to be used in Gerda.

Determination of radium isotopes in environmental samples by gamma spectrometry, liquid scintillation counting and alpha spectrometry: a review of analytical methodology

International Nuclear Information System (INIS)

Jia, Guogang; Jia, Jing

2012-01-01

Radium (Ra) isotopes are important from the viewpoints of radiation protection and environmental protection. Their high toxicity has stimulated the continuing interest in methodology research for determination of Ra isotopes in various media. In this paper, the three most routinely used analytical techniques for Ra isotope determination in biological and environmental samples, i.e. low-background γ-spectrometry, liquid scintillation counting and α-spectrometry, were reviewed, with emphasis on new methodological developments in sample preparation, preconcentration, separation, purification, source preparation and measurement techniques. The accuracy, selectivity, traceability, applicability and minimum detectable activity (MDA) of the three techniques were discussed. It was concluded that the MDA (0.1 mBq L −1 ) of the α-spectrometry technique coupled with chemical separation is about two orders of magnitude lower than that of low-background HPGe γ-spectrometry and LSC techniques. Therefore, when maximum sensitivity is required, the α-spectrometry technique remains the first choice. - Highlights: ► A review is made for determination of Ra isotopes in environmental samples. ► Gamma spectrometry, LSC and a-spectrometry are the main concerned radiometric approach. ► Sample preparation, preconcentration, separation and source preparation are discussed. ► The methods can analyse air, water, seawater, soil, sediment and foodstuffs samples. ► Some new data obtained recently from our laboratory for Ra method study are included.

Measurement of the Rayleigh scattering length in liquid scintillators for JUNO

Energy Technology Data Exchange (ETDEWEB)

Hackspacher, Paul [Johannes Gutenberg-Universitaet Mainz, PRISMA Excellence Cluster (Germany); Collaboration: JUNO-Collaboration

2016-07-01

In liquid scintillator neutrino detectors such as the upcoming Jiangmen Underground Neutrino Observatory (JUNO), neutrino interactions are being detected by means of inverse beta decay and analysis of the resulting luminescent light. In order to reliably reconstruct these events from photomultiplier signals, the scattering properties of the detector materials need to be sufficiently well known. In the LAB-based liquid scintillator that has been proposed for JUNO, the primary contribution to the scattering process comes from Rayleigh scattering. The characteristic Rayleigh scattering length can be experimentally obtained in an optical laboratory setup. This talk presents the approach, the current status and the future plans of the experiment.

Preliminary study of light yield dependence on LAB liquid scintillator composition

International Nuclear Information System (INIS)

Ye Xingchen; Yu Boxiang; Zhou Xiang

2015-01-01

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. (authors)

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

International Nuclear Information System (INIS)

Nogawa, Norio; Makide, Yoshihiro

1999-01-01

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

Counting efficiency formulae for two, three or four photomultiplier systems

International Nuclear Information System (INIS)

Grau Malonda, A.

1993-01-01

Counting efficiency formulae as a function of the non-detection probability and the electron distributions for systems with two, three or dour photomultipliers are obtained in this paper. It is assumed that the photocathode electron emission follows the Poisson distribution. The obtained formulae are basic to compute the counting efficiency in liquid scintillation spectrometers

Ionization and scintillation signals produced by relativistic La ions in liquid argon

Energy Technology Data Exchange (ETDEWEB)

Crawford, H J; Doke, T; Hitachi, H; Kikuchi, J; Lindstrom, P J; Masuda, K; Shibamura, E; Nagamiya, S

1987-04-15

We have observed simultaneously the ionization and scintillation signals produced by relativistic La ions in liquid argon. The two signals are highly correlated and the sums of these signals are constant with the standard deviation of 1.2% over the range of the electric field from 0 to 7.5 kV/cm. The ratio of the sum signals expressed in unit of the number of species to the value N/sub i/ + N/sub ex/ is close to unity where N/sub i/ and N/sub ex/ are the numbers of ion pairs and excitons, respectively, produced by La ions in liquid argon. The pulse height resolution of the sum of the signals is better than that of ionization or scintillation alone. Almost no quenching is found in the scintillation signal from relativistic La ions when compared to signals from lighter ions.

Process for the automatic compensation of spectral displacement based on quenching processes in a liquid scintillation counter

International Nuclear Information System (INIS)

Nather, R.E.

1978-01-01

In measurements in a liquid scintillation counter, the tritium or C 14 isotope to be examined is situated in a scintillator solution. It is excited according to the energy of the β particle to emit light. An electrical signal is proportional to the light signal, and from the former, selective counting in the β spectrum can be undertaken in an impulse height analyser. The influence of the quenching effects by colour quenching or chemical quenching would reduce the gain of the counter. To compensate for the displacement of the spectrum, the required adjustment of a system parameter is carried out by calibration with a sample of low quenching effect. The calibration process is directly set for the energy end-point of the spectrum. Well known processes can be used to determine the quenching effect of the quenching represented by the sample. For example, the system parameters can be the discriminator level of the counter window. (DG) 891 HP [de

The Comparative Accuracy of the 4 {pi} Liquid Scintillation Counting Method of Radioisotope Standardization; L'exactitude comparee de la methode de comptage 4 {pi} a scintillateurs liquides pour l'etalonnage des radioisotopes; Sravnitel'naya tochnost' 4 {pi} zhidkogo stsintillatsionnogo metoda podscheta standartiziruemykh radioizotopov; Exactitud del metodo de recuento con centelleador liquido 4 {pi} para normalizar radioisotopos, comparada con la de otros metodos

Energy Technology Data Exchange (ETDEWEB)

Steyn, J [National Physical Research Laboratory, Pretoria (South Africa)

1960-06-15

The accuracy of the 4 {pi} liquid scintillation counting method of standardizing {beta} emitters was compared to 4 l{pi} {beta}-{gamma} coincidence counting for the nuclides Co{sup 60}, I{sup 131} and Au{sup 198}. For P{sup 32} the liquid counting results were compared to 4 {pi} proportional counting. The efficiency of the liquid scintillation counting method was found to be energy dependent, dropping to about 97.5% for Co{sup 60} which was the lowest energy {beta} emitter investigated. (author) [French] La precision de la methode de comptage 4 {pi} a scintillateurs liquides pour l'etalonnage des emetteurs {beta} a ete comparee au comptage par coincidences 4 {pi} {beta}-{gamma} pour le So{sup 60}, le I{sup 131} et le Au{sup 198}. Dans le cas du P{sup 32}, les resultats du comptage au liquide ont ete compares a ceux du comptage 4 {pi} proportionnel. On a constate que le rendement de la methode de comptage a scintillateurs liquides variait en fonction de l'energie emise et qu'il descendait a environ 97.5% pour le Co{sup 60} qui, de tous les emetteurs {beta} etudies, emet l'energie la plus faible. (author) [Spanish] El autor compara la precision del metodo de recuento con centelleador iquido 4 {pi} para normalizar emisores {beta} con la del metodo de coincidencias {beta}-{gamma} 4 {pi}, para los siguientes nuclidos: So{sup 60}, I{sup 131} y Au{sup 198}. En el caso del P{sup 32}, confronta los resultados del primer metodo con los obtenidos mediante el recuento proporcional 4 {pi}. Comprueba que la eficacia del metodo de recuento con centelleador liquido depende de la energia y desciende al 97.5%, aproximadamente, para el Co{sup 60}, que fue el emisor {beta} mas debil que se investigo. (author) [Russian] Tochnost' 4 {pi} zhidkogo stsintillyatsionnog o metoda podscheta standartiziruemogo {beta}-izluchatelya sravnivalas' s 4 {pi} {beta}-{gamma} metodom podscheta na sovpadeniyakh dlya izotopov So{sup 60}, I{sup 131} i Au{sup 198}. Dlya R{sup 32} rezultaty zhidkogo

Total alpha and beta determination by liquid scintillation counting in water samples from a Brazilian intercomparison exercise

International Nuclear Information System (INIS)

Dias, Fabiana F.; Taddei, Maria Helena T.; Pontedeiro, Elizabeth May Braga Dulley

2009-01-01

This paper describes CNEN/LAPOC's participation in the Brazilian Intercomparison Exercise (PNI) for simultaneous determination of total radioactivity in water samples, which took place in August and December 2008. The Proficiency Test (PT) also involved a short description of the nuclear analytical technique employed, emphasizing sources of uncertainty. A Liquid Scintillation System (Packard TRICARB 2700) was used with appropriate corrections applied to final results, expressed as Bq L -1 . Participation and PT data provide independent information on performance of a Laboratory and have an important role in method validation; especially because it allows the assessment of method performance over an entire range of concentrations and matrices. PT is also an important tool to demonstrate equivalence of measurements, if not their metrological comparability, and to promote education and improvement of Lab practices. (author)

Composition for use in scintillator systems

International Nuclear Information System (INIS)

Tarkkanen, V.

1976-01-01

Reference is made to compositions for liquid scintillation counting of aqueous radioactive samples. A composition is described that reduces chemiluminescence on the addition of an alkaline material. Many common sample materials, for example body fluids, are inherently alkaline, whilst samples such as animal tissues are often dissolved in alkaline media. Another problem is water miscibility, and the object is to provide a scintillation counting composition that, when mixed with an aqueous sample, produces a single phase low viscosity mixture over a wide range of water contents and temperatures. The composition described includes a major amount of an aromatic hydrocarbon solvent, a minor amount of an ethoxylated alkyl phenol surfactant, a scintillation solute, an amount of a substituted ethoxylated carboxylic acid sufficient to reduce chemiluminescence, and an amount of a tertiary amine salt or a quaternary ammonium salt of the substituted ethoxylated carboxylic acid sufficient to enhance the water miscibility. The hydrocarbon solvent and the surfactant may be pre-treated with a reactive solid metal hydride to remove peroxides, and then subsequently pre-treated with SO 2 . Examples of the use of the composition are given. (U.K)

Quality control of radiation counting systems and measurement of minimum detectable activity

International Nuclear Information System (INIS)

Song, Byoung Chul; Han, Sung Sim; Kim, Young Bok; Jee, Kwang Yong; Sohn, Se Chul

2004-01-01

Various radiation counters have been using to determine radioactivity of radwastes for disposal. A radiation counting system was set up using a radiation detector chosen in this study and its stability was investigated through the periodic determination of background and counting efficiencies in accordance with a quality control program to increase the confidence level. The average background level for the γ-spectrometer was 1.59 cps and the average counting level for the standard sample was 45248 dps within 20 confidence levels. The average alpha background level for the low background α/β counting system was 0.31 cpm and the efficiency for alpha counting was 34.38 %. The average beta background level for the α/β counting system was 1.30 cpm and the efficiency for beta counting was 46.5%. The background level in the region of 3H and 14C for the liquid scintillation counting system was 2.52 and 3.31 cpm and the efficiency for alpha counting was 58.5 and 95.6%, respectively. The minimum detectable activity for the γ-spectrometer was found to be 3.2 Bq/mL and 3.8 Bq/mL for the liquid scintillation counter, and 20.5 and 23.0 Bq/mL, respectively for the α and β counting system

The Optimum Condition For Determination Of Radioactivity Of Pest Insects Labelled with P-32 By Using Liquid scintillation Counter

International Nuclear Information System (INIS)

Yarianto, S.; Susilo, Budi; Sutrisno, Singgih

2002-01-01

Tracer technique is needed in the control programe of pest insects especially for determining of its direction and dispersal. Radioisotopes of P-32 is frecuently used for labeling of pest insects. Liquid Scintillation Counter can be used effectively for measuring radioactivity of pest insects labelled by P-32. Optilnization of liquid compositions that consist of solvents. primary scintillation PPO and secondary scintillation POPOP were determined by examination of their compositions. Based on the research result obtained, composition of scintillator which had the highest efficiency. consists of P-Xylene solvent. primary scintillation PPO (5 g/l ) and secondary scintillation POPOP (0.5 g/l)

Measurement of radionuclides using ion chromatography and flow-cell scintillation counting with pulse shape discrimination

International Nuclear Information System (INIS)

DeVol, T.A.; Fjeld, R.A.

1995-01-01

A project has been initiated at Clemson Univ. to develop a HPLC/flow- cell system for analysis of non-gamma emitting radionuclides in environmental samples; an important component is development of a low background flow-cell detector that counts alpha and beta particles separately through pulse shape discrimination. Objective of the work presented here is to provide preliminary results of an evaluation of the following scintillators: CaF 2 :Eu, scintillating glass, and BaF 2 . Slightly acidic aqueous solutions of the alpha emitter 233 U and the beta emitter 45 Ca were used. Detection efficiencies and minimum detectable activities were determined

Virtual point detector: On the interpolation and extrapolation of scintillation detectors counting efficiencies

International Nuclear Information System (INIS)

Presler, Oren; German, Uzi; Pushkarsky, Vitaly; Alfassi, Zeev B.

2006-01-01

The concept of transforming the detector volume to a virtual point detector, in order to facilitate efficiency evaluations for different source locations, was proposed in the past for HPGe and Ge(Li) detectors. The validity of this model for NaI(Tl) and BGO scintillation detectors was studied in the present work. It was found that for both scintillation detectors, the point detector model does not seem to fit too well to the experimental data, for the whole range of source-to-detector distances; however, for source-to-detector cap distances larger than 4 cm, the accuracy was found to be high. A two-parameter polynomial expression describing the dependence of the normalized count rate versus the source-to-detector distance was fitted to the experimental data. For this fit, the maximum deviations are up to about 12%. These deviations are much smaller than the values obtained by applying the virtual point concept, even for distances greater than 4 cm, thus the polynomial fitting is to be preferred for scintillation detectors

Color quench correction for low level Cherenkov counting.

Science.gov (United States)

Tsroya, S; Pelled, O; German, U; Marco, R; Katorza, E; Alfassi, Z B

2009-05-01

The Cherenkov counting efficiency varies strongly with color quenching, thus correction curves must be used to obtain correct results. The external (152)Eu source of a Quantulus 1220 liquid scintillation counting (LSC) system was used to obtain a quench indicative parameter based on spectra area ratio. A color quench correction curve for aqueous samples containing (90)Sr/(90)Y was prepared. The main advantage of this method over the common spectra indicators is its usefulness also for low level Cherenkov counting.

A Procedure for the Rapid Determination of 226Ra and 228Ra in Drinking Water by Liquid Scintillation Counting

International Nuclear Information System (INIS)

2014-01-01

Since 2004, the environment programme of the IAEA has included activities aimed at the development of a set of procedures for the determination of radionuclides in terrestrial environmental samples. Reliable, comparable and ‘fit for purpose’ results are essential requirements for any decision based on analytical measurements. For the analyst, tested and validated analytical procedures are extremely important tools for the production of such data. For maximum utility, such procedures should be comprehensive, clearly formulated and readily available to both the analyst and the customer. This publication describes a procedure for the rapid determination of 226 Ra and 228 Ra in drinking water. The determination of radium in drinking water is important for protecting human health, since the consumption of drinking water containing radium may lead to an accumulation in the body, contributing to the radiological dose. The method is based on the separation of 226 Ra and 228 Ra from interfering elements using PbSO 4 and Ba(Ra)SO 4 coprecipitation steps. The isotopes 226 Ra and 228 Ra are then determined by liquid scintillation counting. The procedure is expected to be of general use to a wide range of laboratories, including the laboratories of the Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) network, both in emergency situations and for routine environmental monitoring purposes. The method was established after an extensive review of papers from the scientific literature, and was tested and validated in terms of repeatability and trueness (relative bias) in accordance with International Organization for Standardization guidelines. Reproducibility tests were performed at expert laboratories. The calculation of massic activities, uncertainty budget, decision threshold and detection limit are also described

Evaluation of the ionization quenching correction for several liquid scintillators

International Nuclear Information System (INIS)

Los Arcos, J. M.; Borras, C.

1990-01-01

The most appropriate computational model for the ionization quenching function Q(E) is analyzed for electrons in liquid scintillators. A numerical evaluation of Q(E) from 0.1 keV to 3 MeV which the kB parameter varying between 0.005 and 0.010 cm/MeV is presented for seven scintillators; Toluene, Toluene-Alcohol, PCS, Toluene-CCl4, INSTAGEL, Dioxane-Naphtalene and HISAFE II. The numerical result are summarized as tables of Ieast squares fitting coefficient which make easy the computation of Q(E). (Author)

Evaluation of the ionization quenching correction for several liquid scintillators

International Nuclear Information System (INIS)

Los Arcos, J.M.; Borras, C.

1990-01-01

The most appropiate computational model for the ionization quench-ing function Q(E) is analyzed for electrons in liquid scintillators. A numerical evaluation of Q(E) from 0.1 keV to 3 MeV which the kB parameter varying between 0.005 and 0.010 cm/MeV is presented for seven scintillators; Toluene, Toluene-Alcohol, PCS, Toluene-CC14, INSTAGEL, Dioxane-Naphtalene and HISAFE II. The numerical result are summarized as tables of least squares fitting coefficient which make easy the computation of Q(E).(Author)

Investigation on n/γ discrimination methods for liquid scintillator detector

International Nuclear Information System (INIS)

Li Kuinian; Li Yang; Zhang Mei; Zhang Zhongbing; Li Binkang; Zhang Xiaodong; Liu Jun; Zhang Xianpeng

2014-01-01

To obtain the n/γ discrimination ability of different digital pulse shape discrimination methods, four methods (rising time method, charge comparison method, pulse gradient analysis and frequency gradient analysis) in americium-beryllium mixed radiation fields were demonstrated. The signals from EJ-301 and BC501A scintillator detectors were digitized using oscilloscope. A comparison was taken among the four discrimination methods. The discrimination results of the four methods in liquid scintillator detectors show that the rising time method is the best and it provides a good choice in real-time n/γ discrimination system. (authors)

Development of a liquid scintillation method for in vitro determination of 226Ra and 228 Ra in bioassay samples

International Nuclear Information System (INIS)

Fernandes, Paulo Cesar P.; Sousa, Wanderson O.; Juliao, Ligia M.Q.C.; Dantas, Bernardo M.

2011-01-01

Radium isotopes are dispersed in the environment according to their physicochemical characteristics. The intake of 226 Ra and 228 Ra in humans can occur by inhalation and ingestion and the risk of internal exposure are related to their long half-lives, characteristics of the emission and biokinetics of the isotopes in the human body. The goal of this work is to develop a methodology for the analysis of 226 Ra and 228 Ra in excreta samples (urine and feces), using liquid scintillation technique. Excreta samples were provided by non-exposed humans for the purpose of standardizing the methodology and the establishment of a background level of radium excretion. Radium isotopes were concentrated and separated from the constituents of the sample by co-precipitation with barium sulphate. The precipitate of Ba(Ra)SO 4 was filtrated and weighted for the determination of the chemical yield. The filter containing the precipitate was transferred to a scintillation vial. In the scintillation vial, 8 mL of water, 8 mL of Instagel XF and 4 mL of UltimaGold were added, forming a gel suspension, after stirring the solution. The 226 Ra and 228 Ra activities were determined 21 days after the precipitation of samples. The samples were counted in a liquid scintillation spectrometer. The technique presented adequate sensitivity and reproducibility for the analysis of urine and feces. The activities of 226 Ra and 228 Ra in excreta samples provide useful information for the identification of the main route of intake and for the assessment of the internal exposure of occupationally exposed workers and inhabitants of high background areas. (author)

A new water-based liquid scintillator and potential applications

Energy Technology Data Exchange (ETDEWEB)

Yeh, M., E-mail: yeh@bnl.gov [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Hans, S.; Beriguete, W.; Rosero, R.; Hu, L.; Hahn, R.L. [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Diwan, M.V.; Jaffe, D.E.; Kettell, S.H.; Littenberg, L. [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

2011-12-21

In this paper we describe a new type of scintillating liquid based on water. We describe the concept, preparation, and properties of this liquid, and how it could be used for a very large, but economical detector. The applications of such a detector range from fundamental physics such as nucleon decay and neutrino physics to physics with broader application such as neutron detection. We briefly describe the scientific requirements of these applications, and how they can be satisfied by the new material.

Determination of 222Rn in water samples from wells and springs in Tokyo by a modified integral counting method

International Nuclear Information System (INIS)

Homma, Y.; Murase, Y.; Handa, K.; Murakami, I.

1997-01-01

222 Rn in 2L-water samples was extracted with 30 mL toluene, and 21 mL of the toluene solution was transferred into a liquid scintillation vial, in which PPO - 2,5-diphenyloxazole was placed in advance. The total activity of 222 Rn in the water sample was calculated based on the Ostwald's coefficient of solubilities of 222 Rn in toluene and water at the temperature of the sample water and the volume of water and toluene. About 40% of 222 Rn dissolved in 2L-water sample can be collected. After allowing to stand for 3.5 h, the equilibrium mixture of 222 Rn and its daughters was measured with an Aloka liquid scintillation spectrometer using a modified integral counting method which extrapolates the integral counting curve not to the zero pulse-height, but to the zero detection threshold, an average energy required to produce a measurable pulse, of the liquid scintillation spectrometer. The general method which agitates water sample (usually about 10 mL) with a liquid scintillation cocktail is practical when the activity of 222 Rn is high. By adding 10 mL of water sample, however, it is possible also to add variable amounts of quencher. In some cases water sample is preserved with nitric acid. The slope of the integral counting rate curve increases as quench level of the sample increases. Therefore, it is clear that the modified integral counting method gives more accurate 222 Rn concentrations for water samples of strong quench than the conventional integral counting method. 222 Rn sample of 0.2 Bq/L can be determined within an overall uncertainty of 3.1%

The study of vial and cocktail for tritium radioactivity analysis of rain water by liquid scintillation counter

International Nuclear Information System (INIS)

Noh, Sung Jin; Kim, Hyo Jin; Kim, Hyun; Lee, Man Woo; Jeong, Dong Hyeok; Yang, Kwang Mo; Kang, Yeong Rok; Nam, Sang Hee

2015-01-01

Even though the current method for tritium (3H) analysis is routine, for the case of the low level of tritium in the environment, special conditions have to be fulfilled in order to obtain accurate and reliable tritium measurements. There are very little comparative data concerning commercial scintillating cocktails. The best cocktails for measuring tritium are those based on benzene derived solvent, and the worse cocktails are those which have complex chemical composition or contain too small concentration of scintillators. The aim of study was to investigate various vials and cocktails by comparison with the combination of few different scintillation cocktails and vials in our routine measurements according to count, efficiency, and the figure of merit (FOM). The comparison of three types of vials with scintillation cocktails for tritium activity analysis of rain water shows that glass vials have higher count rates and HiSafe 3 cocktails have lower FOM

Liquid Scintillation Detectors for High Energy Neutrinos

International Nuclear Information System (INIS)

Smith, Stefanie N.; Learned, John G.

2010-01-01

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.

Electro-removal of H-3 and C-14 contained in scintillation liquid absorbed in soils type Phaeozem

International Nuclear Information System (INIS)

Valdovinos, V.; Bustos, E.; Monroy G, F.

2014-10-01

This paper presents the results of electro-removal, an electrochemical treatment in soils contaminated with H-3 and C-14 contained in scintillation liquids absorbed in soils. For this purpose the best electrochemical conditions were used, which are: scintillation liquid Ultima Gold Xr, water (1:1) and 1 m A in the passage of current. The media were characterized before and after of applying the different potentials by various analytical techniques, such as: liquids by gas chromatography with a flame ionization detector, solids and liquids by Fourier transform infrared spectroscopy (Ftir) and electrodes by scanning electron microscopy with elemental analysis by energy-dispersive X-ray spectroscopy. Later standard samples with H-3 and C-14 were prepared and the electrochemical treatment was applied to previously established conditions. After electrochemical treatment the scintillation liquid characterization was performed by gas chromatography and a scintillation counter to see the disintegrations per minute. According to results of Ftir, soils show no deterioration and in the liquid phase the amount of water increases as the applied potential, due to oxidation-reduction reactions where happen modification or mineralization of organic molecules (H 2 O and CO 2 formation). In 4 h of treatment, removal percentages in the liquid phase, were: 53.6% of H-3 and 11.6% of C-14. (Author)

Method for calibration measurement in a liquid scintillation counter and carrier used in the method

International Nuclear Information System (INIS)

Reunanen, M.A.

1976-01-01

The present invention relates to a method for use in liquid scintillation measurements to feed an accurately determined amount of radioactive substance to a fluid scintillation system for a calibration measurement. According to the invention an accurately determined amount of radioactive substance is adsorbed to a carrier, which is introduced into the fluid scintillation system. The invention also relates to a carrier for use in the method

Measurement by liquid scintillation of 226 Ra coprecipitated in BaSO4

International Nuclear Information System (INIS)

Lopez del Rio, H.; Davila R, J.I.; Badillo A, V.E.; Mireles G, F.; Quirino T, L.; Lugo R, J.F.; Pinedo V, J.L.; Rios M, C.

2003-01-01

The 226 Ra is one of the more radio toxic nuclides since when entering to the organism it continues metabolically to the calcium, accumulating mainly in the bone tissue where it becomes in an internal radiation source. For the analysis of radium in water the methods of radon emanation are generally applied and coprecipitation with barium sulfate. This last is quick and efficient, and the radium in the precipitate can be measured by alpha or gamma spectrometry, or liquid scintillation dissolving the precipitate one with EDTA. In this work it is proposed a procedure for the radium measurement in water based on the coprecipitation with barium sulfate and in the detection by liquid scintillation. The precipitate of Ba(Ra)SO 4 it is carried with water and blended with the liquid scintillator OptiPhase Hi Safe 3, avoiding the dissolution with EDTA. A 92± 1.4% of radium it was recovered and it was reached a minimum activity detectable of 4.2 ± 0.9 mBq -1 . The procedure was essayed with natural mineral water with a knew activity in concentration of 226 Ra. The analytic result it coincided with the reported value with a relative error of 9%. (Author)

Scintillation detector with anticoincidence shield for determination of the radioactive concentration of standard solutions

International Nuclear Information System (INIS)

Broda, R.; Radoszewski, T.

1982-01-01

The construction and parameters of the prototype liquid scintillation detector for disintegration rate determination of standard solutions is described. The detector is equipped with a liquid scintillation anticoincidence shield with a volume of 40 l. The instrument is placed in the building of the Radioisotope Production and Distribution Centre in the Institute of Nuclear Research at Swierk. The results of instrument background reduction are described. The counting efficiency of several beta-emitters 3 H, 63 Ni, 14 C and 90 Sr + 90 Y is given, as well as the examples of a disintegration rate determination of low radioactivity concentration of standard solutions. (author)

Measurement of gross alpha and beta in air filter samples by using liquid scintillation counter

International Nuclear Information System (INIS)

Sudheendran, V.; Baburajan, A.; Gaikwad, R.H.; Ravi, P.M.; Tripathi, R.M.

2015-01-01

The determination of gross alpha and gross beta in particulate air filter samples was carried out by alpha, beta discrimination method using Liquid Scintillation Analyzer by setting the PSA value at 55 for 5 ml 0.1 HCl plus 15 ml of Ultima Gold AB cocktail by using 241 Am and 90 Sr/ 90 Y sources. The standardized method was compared with the gross alpha and gross beta activity determined by conventional method of direct counting with end window G.M. counter and ZnS (Ag). The minimum detectable activity of LSA method was found to be 9.3 mBq and 17.7 mBq for gross alpha and gross beta respectively for 6000 sec compared to the conventional method of 9.8 mBq and 189 mBq respectively at the same counting time. The result of analysis by both method indicate that the alpha, beta discrimination set up of LSA method is highly effective in the determination of low level alpha, beta activity in air filter samples. (author)

Removal of actinide elements from liquid scintillation cocktail wastes using liquid-liquid extraction and demulsification techniques

International Nuclear Information System (INIS)

Foltz, K.; Landsberger, S.; Srinivasan, B.; Vandegrift, G.F.

1994-01-01

For many years liquid scintillation cocktail (LSC) wastes have been generated and stored at Argonne National Laboratory (ANL). These wastes are stored in thousands of 10--20 m scintillation vials, many of which contain elements with Z > 88. Because storage space is limited, disposal of this waste is pressing. These wastes could be commercially incinerated if the radionuclides with Z>88 are reduced to sufficiently low levels. However, there is currently no deminimus level for these radionuclides, and separation techniques are still being tested. The University of Illinois is conducting experiments to separate radionuclides with Z > 88 from simulated LSC wastes by using liquid-liquid extraction (LLX) and demulsification techniques. The actinide elements are removed from the LSC by extraction into an aqueous phase after the cocktail has been demulsified. The aqueous and organic phases are separated and the organic phase, now free from radionuclides with Z > 88, can be sent to a commercial incineration facility. The aqueous phase may be treated and disposed of using existing techniques. The LLX separation techniques used solutions of sodium oxalate, aluminum nitrate, and tetrasodium EDTA at varying concentrations. These extractants were mixed with the simulated waste in a 1:1 volume ratio. Using 1.0M Na 4 EDTA salt solutions, decontamination ratios as high as 230 were achieved

Application of a free parameter model to plastic scintillation samples

Energy Technology Data Exchange (ETDEWEB)

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

2011-08-21

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

Ionization and scintillation produced by relativistic Au, He and H ions in liquid argon

Energy Technology Data Exchange (ETDEWEB)

Shibamura, E; Masuda, K; Crawford, H J; Engelage, J M; Doke, T; Hitachi, A; Kikuchi, J; Flores, I; Lindstrom, P J; Ogura, K

1987-10-15

We have measured ionization and scintillation produced by relativistic ions of Au, He and H in liquid argon. The sum of ionization signal and scintillation signal per unit energy deposition is the same for He and H ions, which is also the same as that for relativistic Ne, Fe and La ions previously measured. We have found that quenching occurs when liquid argon is irradiated by relativistic Au ions and that the sum per unit energy deposition for the Au ions is 70-76% of that for the other ions mentioned above.

A new liquid xenon scintillation detector for positron emission tomography

International Nuclear Information System (INIS)

Chepel, V.Yu.

1993-01-01

A new positron-sensitive detector of annihilation photons filled with liquid xenon is proposed for positron emission tomography. Simultaneous detection of both liquid xenon scintillation and ionization current produces a time resolution of < 1 ns and a position resolution in the tangential direction of the tomograph ring is ∼ 1 mm and in the radial direction is ∼ 5 mm. The advantages of a tomograph with new detectors are discussed. New algorithms of Compton scattering can be used. (author)

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

International Nuclear Information System (INIS)

Perez Sanchez, D.; Martin Sanchez, A.; Jurado Vargas, M.

2003-01-01

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

Marine radioactivity measurements with liquid scintillation spectrometers

International Nuclear Information System (INIS)

Liong Wee Kwong, L.; Povinec, P.P.

1999-01-01

Liquid Scintillation Spectrometry (LSS) has now become the most widespread method for quantitative analytical measurement of low levels of β-emitting radionuclides like 3 H and 14 C. The high efficiency resulting from the latest development in LSS makes this technique not only appropriate but also enables direct measurement in environmental samples without excessive preparation. The introduction of several new cocktails based on solvents with a high flashpoint containing surfactants and having a high degree of aqueous sample compatibility has also contributed to the simplification of procedures

Determining reactor fuel elements broken by Cerenkov counting

International Nuclear Information System (INIS)

Guo Juhao; Dong Shiyuan; Feng Yuying

1996-01-01

The basis and method of determining fuel elements broken in a reactor by Cerenkov counting measured with liquid scintillation spectrometer are introduced. The radioactive characteristic of the radiation nuclides generating Cherenkov radiation in the primary water of 200 MW nuclear district heating reactor is analyzed. The activity of the activation products in the primary water and the fission products in the fuel elements are calculated. A feasibility of Cerenkov counting measure was analyzed. This method is simple and quick

Response of gadolinium doped liquid scintillator to charged particles: measurement based on intrinsic U/Th contamination

Science.gov (United States)

Du, Q.; Lin, S. T.; He, H. T.; Liu, S. K.; Tang, C. J.; Wang, L.; Wong, H. T.; Xing, H. Y.; Yue, Q.; Zhu, J. J.

2018-04-01

A measurement is reported for the response to charged particles of a liquid scintillator named EJ-335 doped with 0.5% gadolinium by weight. This liquid scintillator was used as the detection medium in a neutron detector. The measurement is based on the in-situ α-particles from the intrinsic Uranium and Thorium contamination in the scintillator. The β–α and the α–α cascade decays from the U/Th decay chains were used to select α-particles. The contamination levels of U/Th were consequently measured to be (5.54±0.15)× 10‑11 g/g, (1.45±0.01)× 10‑10 g/g and (1.07±0.01)× 10‑11 g/g for 232Th, 238U and 235U, respectively, assuming secular equilibrium. The stopping power of α-particles in the liquid scintillator was simulated by the TRIM software. Then the Birks constant, kB, of the scintillator for α-particles was determined to be (7.28±0.23) mg/(cm2ṡMeV) by Birks' formulation. The response for protons is also presented assuming the kB constant is the same as for α-particles.

Determination of 226Ra by alpha spectrometry of liquid scintillation

International Nuclear Information System (INIS)

Nobrega, A.W.; Sachett, I.A.; Hespanhol, E.C.B.

1987-01-01

The determination of 226 Ra in environmental samples using alpha spectrometry in liquid scintilation is studied. The Radon 1-2 emanation method and 226 Ra separation process of other radionuclides alpha emissors are analyzed. The use of 226 Ra coprecipitation with barium sulphate is evaluated. (M.J.C.) [pt

Study on efficiency calibration of tritium in liquid scintillation spectrometry

International Nuclear Information System (INIS)

Zhai Xiufang; Wang Yaoqin; Li Weiping; Liang Wei; Xu Hui; Zhang Ruirong

2014-01-01

The method for efficiency calibration of tritium sample in liquid scintillation spectrometry was presented. The quenching effects from different chemical quenchers (Acidbase, CH_3NO_2, CCl_4, CH_3COCH_3) and color quencher (Na_2CrO_4) were studied. For each quencher, the methods of sample channel ratio (SCR), spectrum index of the sample (SIS) and spectral quenching parameter of the external standard (SQP (E)) were used for efficiency calibration respectively, and three methods were compared. The results show that the quenching from the various chemical quencher can be unified for one chemical quenching for efficiency calibration. There is great difference in the correction curves of chemical quenching and color quenching, and the fact is independent of the used efficiency calibration method. The SCR method is not advantageous for the tritium sample with low radioactivity or strong quenching. The SQP (E) method is independent of the sample count rate, and it is especially suitable for the efficiency calibration of low radioactivity tritium. The SIS method can be used for samples with high radioactivity. The accurate efficiency calibration for various quenching can be carried out by combining the SIS method and the SQP (E) method. (authors)

Liquid scintillation counting

International Nuclear Information System (INIS)

Bunge, F.

1986-01-01

The methods applied for quench corrections in LSC rely on radioactivity standard sources as reference materials. For determining the quenching effect effect, there are methods based on the sample channel ratio, or the spectral quench parameter determination, or determination of the H-number. Currently available LSC equipment is briefly described. (DG) [de

High energy gamma ray response of liquid scintillator

International Nuclear Information System (INIS)

Shigyo, N.; Ishibashi, K.; Matsufuji, N.; Nakamoto, T.; Numajiri, M.

1994-01-01

We made the experiment on the spallation reaction. NE213 organic liquid scintillators were used for measuring neutrons and γ rays. To produce the γ ray emission cross section, we used the response functions by EGS4 code. The response functions look like uniform above γ ray energies of 60 MeV. The experimental data of the γ ray emission cross section are different from the data of High Energy Transport Code. (author)

Determination of 90Sr in radioactive liquid waste-a comparative study using 'SrCO3 precipitation, extraction chromatography and Cerenkov radiation counting' techniques

International Nuclear Information System (INIS)

Mani, A.G.S.; Renganathan, K.; Rao, S.V.S.; Sinha, P.K.

2007-01-01

In the wastes generated at nuclear power plants, 90 Sr and 90 Y are responsible for approximately 7% and 38% of the total fission product activity after 1 year and 10 years respectively. Monitoring of the liquid waste produced in nuclear facilities for 90 Sr before and after releasing to the aquatic environment is essential, as it can cause a long term biological hazard due to its chemical similarity with Ca, high fission yield (5.9%) and long radioactive and biological half lives of 28 and 49.3 years respectively. As conventional carbonate precipitation method for 90 Sr- 90 Y estimation is laborious and time consuming, the other methods like extraction chromatography technique using strontium selective crown ether and Cerenkov radiation counting by liquid scintillation analyser (LSA) were also investigated. This paper describe procedures involved in the estimation of strontium in low-level radioactive liquid effluent by using above methods and deals with the comparison of results. Cerenkov radiation counting by LSA has an edge over the other methods in the determination of 90 Sr as it is a simple and rapid technique. Experiences gained in the estimation of 90 Sr in low-level radioactive liquid effluent using Cerenkov radiation counting technique is discussed in detail in this paper. (author)

Development of a liquid scintillation method for in vitro determination of {sup 226}Ra and {sup 228} Ra in bioassay samples

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Paulo Cesar P.; Sousa, Wanderson O.; Juliao, Ligia M.Q.C.; Dantas, Bernardo M., E-mail: pcesar@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2011-07-01

Radium isotopes are dispersed in the environment according to their physicochemical characteristics. The intake of {sup 226}Ra and {sup 228}Ra in humans can occur by inhalation and ingestion and the risk of internal exposure are related to their long half-lives, characteristics of the emission and biokinetics of the isotopes in the human body. The goal of this work is to develop a methodology for the analysis of {sup 226}Ra and {sup 228}Ra in excreta samples (urine and feces), using liquid scintillation technique. Excreta samples were provided by non-exposed humans for the purpose of standardizing the methodology and the establishment of a background level of radium excretion. Radium isotopes were concentrated and separated from the constituents of the sample by co-precipitation with barium sulphate. The precipitate of Ba(Ra)SO{sub 4} was filtrated and weighted for the determination of the chemical yield. The filter containing the precipitate was transferred to a scintillation vial. In the scintillation vial, 8 mL of water, 8 mL of Instagel XF and 4 mL of UltimaGold were added, forming a gel suspension, after stirring the solution. The {sup 226}Ra and {sup 228}Ra activities were determined 21 days after the precipitation of samples. The samples were counted in a liquid scintillation spectrometer. The technique presented adequate sensitivity and reproducibility for the analysis of urine and feces. The activities of {sup 226}Ra and {sup 228}Ra in excreta samples provide useful information for the identification of the main route of intake and for the assessment of the internal exposure of occupationally exposed workers and inhabitants of high background areas. (author)

System of the incineration for the liquid scintillation garbage

International Nuclear Information System (INIS)

Naba, Katsumi

1981-12-01

In Japan from 1980 the incineration of the used scintillation liquid has been permitted according to the safety guide regulation of Japan Scientific Technology Agency. This incineration method would disperse the radioactivity in local site and destroy the chemicals at the same time. This system are consist of three parts. (1) Filtration and pH. adjustment of liquid garbage. (2) Bubbling vaporization in closed cycle. The temperature of the solution inside vessel is kept from 65 0 C to 85 0 C and the solution is bubbled with nealy 4 0 C circulated air. After the end of distillation, water layer is separated from the organic chemical layer and put it down the drain according to the regulation. (3) The residue is mixed with only the distilled organic chemicals according to the next classification, thereafter incineration is carried out. (a) For under the radioactive concentration of 1 x 10 -3 μCi/ml, the mixed scintillation liquid are burned up in specially designed incinerator. (b) For over the level of 1 x 10 -3 μCi/ml, only the distilled organic chemicals are burned up and the residue will be sent to the Waste Disposal Site. (c) For under the water content of 5% these liquid garbage can be directly are burned up without distillation The residue seemed to be suitable for the combustion of the dried carcased animals as the auxiliary fuels. This incinerator will be able to use as room heater or water heater for the bath without radioactive contamination inside of install room. (author)

Tritium Activity Measurement of Water Samples Using Liquid Scintillation Counter and Electrolytical Enrichment

International Nuclear Information System (INIS)

Baresic, J.; Krajcar Bronic, I.; Horvatincic, N.; Obelic, B.; Sironic, A.; Kozar-Logar J.

2011-01-01

Tritium (3H) activity of natural waters (precipitation, groundwater, surface waters) has recently become too low to be directly measured by low-level liquid scintillation (LSC) techniques. It is therefore necessary to perform electrolytical enrichment of tritium in such waters prior to LSC measurements. Electrolytical enrichment procedure has been implemented at the Rudjer Boskovic Institute (RBI) Tritium Laboratory in 2008, and since then 19 electrolyses have been completed. The mean enrichment factor E (a ratio between the final and initial 3H activities) after stabilisation of the system is E R BI = 22.5 @ 0.5, and the mean enrichment parameter (which describes the process of water mass reduction during electrolysis) is P R BI 0.949 @ 0.003. These values are comparable with those obtained at the Jo@ef Stefan Institute (JSI) Laboratory for liquid scintillation counting, at the electrolysis equipment of the same producer (AGH University of Science and Technology, Krakow, Poland) after 66 electrolyses carried out under identical conditions since 2007: E J SI = 18.9 @ 1.5, and P J SI = 0.896 @ 0.021. Both RBI and JSI laboratories have Ultra-low-level LSC Quantulus 1220 (Wallac, PerkinElmer) for measurement of 3H activity. A set of water samples having 3H activities in the range from 0 TU (''dead-water'' samples) to 18 000 TU (1 TU 0.118 Bq/L) were measured at both laboratories. Samples having 3H activity <200 TU were electrolytically enriched, while the others were measured directly in LSC. A very good agreement was obtained (correlation coefficient 0.991). Both laboratories participated in the IAEA TRIC2008 international intercomparison exercise. The analyses of reported 3H activity results in terms of z and u parameters showed that all results in both laboratories were acceptable. (author)

Performances and stability of a 2.4 ton Gd organic liquid scintillator target for ν-bar e detection

International Nuclear Information System (INIS)

Barabanov, I R; Bezrukov, L B; Danilov, N A; Krilov, Yu S; Yanovich, E A; Malguin, A S; Cattadori, C M; Vacri, A di; Ioannucci, L; Bruno, G; Aglietta, M; Bonardi, A; Fulgione, W; Porta, A; Kemp, E; Selvi, M

2010-01-01

In this paper we report the performance and the chemical and physical properties of a 2 x 1.2 ton organic liquid scintillator target doped with Gd up to ∼ 0.1%, and the results of a 3 year long stability survey of the target. In particular we have measured and monitored the optical and fluorescent properties of the Gd-doped liquid scintillator (LS), the amount of both Gd and primary fluor in solution, and the performance of the two Gd doped targets as neutron detectors, namely neutron capture efficiency and average capture time. The experimental survey is ongoing, the targets being continuously monitored. From the spectrophotometric measurements performed on samples periodically extracted along the three years, we can exclude, at 99% C.L. level, a degradation of the light transmittance of the Gd-doped liquid scintillator larger than 1% y -1 ; from the in-tank measurements no significant decrease of the neutron capture efficiency and neutron capture time is observed. This is the largest stable Gd-doped organic liquid scintillator target ever produced and continuously operated for a long period.

Radon counting statistics - a Monte Carlo investigation

International Nuclear Information System (INIS)

Scott, A.G.

1996-01-01

Radioactive decay is a Poisson process, and so the Coefficient of Variation (COV) of open-quotes nclose quotes counts of a single nuclide is usually estimated as 1/√n. This is only true if the count duration is much shorter than the half-life of the nuclide. At longer count durations, the COV is smaller than the Poisson estimate. Most radon measurement methods count the alpha decays of 222 Rn, plus the progeny 218 Po and 214 Po, and estimate the 222 Rn activity from the sum of the counts. At long count durations, the chain decay of these nuclides means that every 222 Rn decay must be followed by two other alpha decays. The total number of decays is open-quotes 3Nclose quotes, where N is the number of radon decays, and the true COV of the radon concentration estimate is 1/√(N), √3 larger than the Poisson total count estimate of 1/√3N. Most count periods are comparable to the half lives of the progeny, so the relationship between COV and count time is complex. A Monte-Carlo estimate of the ratio of true COV to Poisson estimate was carried out for a range of count periods from 1 min to 16 h and three common radon measurement methods: liquid scintillation, scintillation cell, and electrostatic precipitation of progeny. The Poisson approximation underestimates COV by less than 20% for count durations of less than 60 min

Variable sampling-time technique for improving count rate performance of scintillation detectors

International Nuclear Information System (INIS)

Tanaka, E.; Nohara, N.; Murayama, H.

1979-01-01

A new technique is presented to improve the count rate capability of a scintillation spectrometer or a position sensitive detector with minimum loss of resolution. The technique is based on the combination of pulse shortening and selective integration in which the integration period is not fixed but shortened by the arrival of the following pulse. Theoretical analysis of the degradation of the statiscal component of resolution is made for the proposed system with delay line pulse shortening, and the factor of resolution loss is formulated as a function of the input pulse rate. A new method is also presented for determining the statistical component of resolution separately from the non-statistical system resolution. Preliminary experiments with a NaI(Tl) detector have been carried out, the results of which are consistent with the theoretical prediction. However, due to the non-exponential scintillation decay of the NaI(Tl) crystal, a simple delay line clipping is not satisfactory, and an RC high-pass filter has been added, which results in further degradation of the statistical resolution. (Auth.)

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

International Nuclear Information System (INIS)

Persiani, R.; Garbini, M.; Sartorelli, G.; Selvi, M.

2013-01-01

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 −4 and (1.5±0.3)×10 −3 in liquid scintillator and in stainless steel, respectively

Study of a system for tritium analysis in water by electrolytic enrichment and liquid scintillation

International Nuclear Information System (INIS)

Pane, L.

1979-01-01

A system for the measurement of the low-level tritium concentrations in water samples has been experimentally studied. The enrichment of the samples is performed through electrolysis in twenty cells connected in series, and the counting is made in a liquid scintillation counter. Several parameters that could affect the accuracy of the results are analysed and the optimization of the system is discussed. For a sample volume reduction from 1000 to 15ml, the recovery of tritium, during electrolysis is of 63% and the enrichment factor is about 40. The lowest detection limit of the system is 1.0+-0.5 U.T. Its analytical capacity is of 30 samples a month. The results obtained in the determination of 3 H concentration in a series of samples from rain, surface and underground waters can be considered satisfactory. (Author) [pt

Method validation for simultaneous counting of Total α , β in Drinking Water using Liquid Scintillation Counter

International Nuclear Information System (INIS)

Al-Masri, M. S.; Nashawati, A.

2014-05-01

In this work, Method Validation Methods and Pulse Shape Analysis were validated to determine gross Alpha and Beta Emitters in Drinking Water using Liquid Scintillation Counter Win spectral 1414. Validation parameters include Method Detection Limit, Method Quantitation Limit, Repeatability Limit, Intermediate Precision, Trueness) Bias), Recovery Coefficient, Linearity and Uncertainty Budget in analysis. The results show that the Method Detection Limit and Method Quantitation Limit were 0.07, 0.24 Bq/l for Alpha emitters respectively, and 0.42, 1.4 Bq/l for Beta emitters, respectively. The relative standard deviation of Repeatability Limit reached 2.81% for Alpha emitters and 3.96% for Beta emitters. In addition to, the relative standard deviation of Intermediate Precisionis was 0.54% for Alpha emitters and 1.17% for Beta emitters. Moreover, the trueness was - 7.7% for Alpha emitters and - 4.5% for Beta emitters. Recovery Coefficient ranged between 87 - 96% and 88-101 for Alpha and Beta emitters, respectively. Linearity reached 1 for both Alpha and Beta emitters. on the other hand, Uncertainty Budget for all continents was 96.65% ,83.14% for Alpha and Beta emitters, respectively (author).

Interference of dissolved salts in Cerenkov and liquid scintillation estimation of 90Sr

International Nuclear Information System (INIS)

Pulhani, Vandana; Jha, S.K.; Tripathi, R.M.; Reddy, Priyanka; Bhade, Sonali

2014-01-01

Quenching is the most important effect occurring in Cerenkov and LSC because it affects the efficiency of conversion of β particles into light. Bore well water samples are very often concentrated by evaporation to reduce the detection limit which can also increase the dissolved solid content (TDS) in the sample. Some ground waters are inherently having higher TDS. Self-absorption of beta-particle radiation by the sample especially the lower-energy beta particles depends on sample thickness and density. Environmental samples, after applying the radiochemical procedure, are also estimated by Cerenkov/LSC and might be affected by colour quenching. To get best measurements using Liquid Scintillation and Cerenkov radiations, it is necessary to avoid high salt concentrations and colors which may weaken energy transfers within scintillator cocktails and sample medium. Therefore the degree of self-absorption and quench should be evaluated and taken into account in the calibration. Efficiency is represented as a function spectral quench parameter of external standard SQP(E). The quenching effect of dissolved solids on the efficiency of estimation of 90 Sr by Cerenkov and Liquid Scintillation are studied

Testing the count rate performance of the scintillation camera by exponential attenuation: Decaying source; Multiple filters

International Nuclear Information System (INIS)

Adams, R.; Mena, I.

1988-01-01

An algorithm and two fortrAN programs have been developed to evaluate the count rate performance of scintillation cameras from count rates reduced exponentially, either by a decaying source or by filtration. The first method is used with short-lived radionuclides such as 191 /sup m/Ir or 191 /sup m/Au. The second implements a National Electrical Manufacturers' Association (NEMA) protocol in which the count rate from a source of 191 /sup m/Tc is attenuated by a varying number of copper filters stacked over it. The count rate at each data point is corrected for deadtime loss after assigning an arbitrary deadtime (tau). A second-order polynomial equation is fitted to the logarithms of net count rate values: ln(R) = A+BT+CT 2 where R is the net corrected count rate (cps), and T is the elapsed time (or the filter thickness in the NEMA method). Depending on C, tau is incremented or decremented iteratively, and the count rate corrections and curve fittings are repeated until C approaches zero, indicating a correct value of the deadtime (tau). The program then plots the measured count rate versus the corrected count rate values

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

Method of measuring the disintegration rate of a beta-emitting radionuclide in a liquid sample

International Nuclear Information System (INIS)

Horrocks, D.L.

1980-01-01

A novel liquid scintillation counting method of measuring the disintegration rate of a beta-emitting radionuclide is described which involves counting the sample at at least two different quench levels. (UK)

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

Science.gov (United States)

Alsanea, F.; Beddar, S.

2017-05-01

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

Determination of the plutonium contamination level in biological samples by liquid scintillation

International Nuclear Information System (INIS)

Willemot, J.M.; Verry, M.; Lataillade, G.

1989-01-01

Usual radiochemical processes are unable to carry out without delay the very large number of analyses as required in plutonium toxicology studies. Liquid scintillation is the best method to quickly determine plutonium contamination levels in most various samples (bone, organs,...) [fr

Determination of radon concentration in ground water in Aichi Prefecture by liquid scintillation counter

Energy Technology Data Exchange (ETDEWEB)

Onuma, A.; Shimizu, M.; Chaya, K.; Hamamura, N. (Aichi Prefectural Inst. of Public Health, Nagoya (Japan)); Kagami, T.

1982-01-01

The radon (Rn) concentration in ground water in Aichi Prefecture was determined by the liquid scintillation counter (LSC) method. The measurement of radon by LSC was made by integration counting, keeping the constant LS quantity in a vial and the constant geometry of a photomultiplier. The recovery rate of radon with 226-radium standard solution was 98.7%. The coefficient of variation in the measured values of radon concentration in ground water in Aichi Prefecture by the LSC method was 4.9%. For the same ground waters in the prefecture, the radon concentrations measured by the LSC method and by the conventional IM fontactoscope method were examined comparatively. This gave a regression formula of LSC value = 0.583 x IM value + 1.325 (n = 70, coefficient of correlation 0.966), indicating significant correlation between the two. It is thus shown that the LSC method is an effective means as the IM fontactoscope method.

Determination of radon concentration in ground water in Aichi Prefecture by liquid scintillation counter

International Nuclear Information System (INIS)

Onuma, Akiko; Shimizu, Michihiko; Chaya, Kunio; Hamamura, Norikatsu; Kagami, Tadaaki.

1982-01-01

The radon (Rn) concentration in ground water in Aichi Prefecture was determined by the liquid scintillation counter (LSC) method. The measurement of radon by LSC was made by integration counting, keeping the constant LS quantity in a vial and the constant geometry of a photomultiplier. The recovery rate of radon with 226-radium standard solution was 98.7%. The coefficient of variation in the measured values of radon concentration in ground water in Aichi Prefecture by the LSC method was 4.9%. For the same ground waters in the prefecture, the radon concentrations measured by the LSC method and by the conventional IM fontactoscope method were examined comparatively. This gave a regression formula of LSC value = 0.583 x IM value + 1.325 (n = 70, coefficient of correlation 0.966), indicating significant correlation between the two. It is thus shown that the LSC method is an effective means as the IM fontactoscope method. (J.P.N.)

A comparative study of 19-iodo cholesterol-125I 3-acetate and Na 125I in liquid scintillation measurements; Estudio comparativo del acetato de 19-iodocolesterol- -125I con Nal25I en medidas por centelleo liquido

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

1994-07-01

A comparative study of performance of 19-iodo cholesterol {sup 1}25I 3-acetate and sodium iodide samples labeled with 125I is presented for liquid scintillation counting measurements. Quench effect, count rate stability and spectral evolution of samples have been followed for several weeks in Toluene, Hisafe II, Instagel, Dioxane-naphthalene and Toluene-alcohol scintillators. Organic samples have negligible quench effect in the interval of I concentration of 0-90 {mu}g and inorganic samples only show a very small variation, lower than 12%, for Dioxane-naphthalene, in the same range of concentration. Satisfactory stability is obtained in general for both, organic and inorganic samples, but small counting losses, 0.03% for 19-iodocholesterol 1 I 3-acetate samples in Tolue ne-alcohol and 0 .04% for Na 125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs.

Measurement of radon 222 in drinking water and air by liquid scintillation

International Nuclear Information System (INIS)

Schoenhofer, F.

1991-01-01

This is a brief description of the liquid scintillation measuring method for determining radon 222 in drinking water and air. Discussed are the advantages of this method and its reliability or accuracy, as well as some conclusions from the results. (orig.) [de

Fast technetium Eigen-colloid determination: preparative CPC combined with suspension liquid scintillation

International Nuclear Information System (INIS)

Breynaert, E.; Maes, A.

2005-01-01

Full text of publication follows: Both medical and environmental studies concerned with the solubility and the complexation chemistry of technetium have encountered colloidal Tc(IV)-forms. Although the existence of the Tc colloids has been proven by various techniques [1-6], their determination still remains an issue. Recently a Column Precipitation Chromatography (CPC) technique was developed which enabled the quantitative determination of technetium Eigen-colloids. Based on this technique, a solid phase extraction (SPE)-like methodology was developed that can be used in combination with suspension liquid scintillation to provide a fast analysis of the Eigen-colloid content of a sample. The CPC technique is a thorough analysis methodology for the quantitative determination of the Eigen-colloid content of a sample containing reduced technetium species. This technique requires a relative long elution scheme and fractionation of the eluate. The fractionation also implies a relatively long counting time to determine the Eigen-colloid activity of a sample. Currently an SPE-like analysis methodology was developed which combines a good estimate of the Eigen-colloid content with fast analysis times. To construct a methodology providing both features a specialized extraction apparatus was constructed and a quantitative suspension liquid scintillation technique was developed. This combination enables the Eigen-colloid determination within a short experimental time (15 min) and a limited counting time (60 min). The authors acknowledge a grant from KULeuven University and financial support from the KULeuven Geconcerteerde Onderzoeksacties (GOA2000/007). We also kindly acknowledge NIRAS/ONDRAF for financial support from Contract CCHO 20004004862 [1] Grossmann, B. and R. Muenze, Relationship between complex formation by 99 Tc(IV) and the chemical structure of aliphatic carboxylic acid ligands. The International Journal of Applied Radiation and Isotopes, 1982. 33(3): p. 189

Determination of /sup 226/Ra by alpha spectrometry of liquid scintillation

Energy Technology Data Exchange (ETDEWEB)

Nobrega, A W; Sachett, I A; Hespanhol, E C.B.

1987-07-01

The determination of /sup 226/Ra in environmental samples using alpha spectrometry in liquid scintilation is studied. The Radon/sup 1-2/ emanation method and /sup 226/Ra separation process of other radionuclides alpha emissors are analyzed. The use of /sup 226/Ra coprecipitation with barium sulphate is evaluated. (M.J.C.).

Scintillation efficiency of nuclear recoil in liquid xenon

CERN Document Server

Arneodo, F; Badertscher, A; Benetti, P; Bernardini, E; Bettini, A; Borio di Tigliole, A A; Brunetti, R; Bueno, A G; Calligarich, E; Campanelli, M; Carpanese, C; Cavalli, D; Cavanna, F; Cennini, P; Centro, Sandro; Cesana, A; Cline, D; De Mitri, I; Dolfini, R; Ferrari, A; Gigli-Berzolari, A; Matthey, C; Mauri, F; Mazza, D; Mazzone, L; Meng, G; Montanari, C; Nurzia, G; Otwinowski, S; Palamara, O; Pascoli, D; Pepato, Adriano; Petrera, S; Periale, L; Piano Mortari, G; Piazzoli, A; Picchi, P; Pietropaolo, F; Rancati, T; Rappoldi, A; Raselli, G L; Rebuzzi, D; Revol, Jean Pierre Charles; Rico, J; Rossella, M; Rossi, C; Rubbia, André; Rubbia, Carlo; Sala, P; Scannicchio, D A; Sergiampietri, F; Suzuki, S; Terrani, M; Tian, W; Ventura, Sandro; Vignoli, C; Wang, H; Woo, J; Xu, Z

2000-01-01

We present the results of a test done with a Liquid Xenon (LXe) detector for 'Dark Matter' search, exposed to a neutron beam to produce nuclear recoil events simulating those which would be generated by WIMP's elastic scattering. The aim of the experiment was to measure directly the scintillation efficiency of nuclear recoil. The nuclear recoil considered in the test was in the tens of keV range. The ratio of measured visible energy over the true recoil energy was evaluated to be about 20%, in good agreement with the theoretical predictions.

A liquid scintillator detector for the solar neutrino

Energy Technology Data Exchange (ETDEWEB)

Ranucci, G [Lab. Nazionali del Gran Sasso, Assergi (Italy) Massachusetts Inst. of Technology, Cambridge, MA (United States) Joint Inst. for Nuclear Research, Dubna (USSR) Technical Univ. of Munich, Garching (Germany) Physics Dept., Univ. Genova (Italy) INFN, Genova (Italy) Univ. Hawaii, Honolulu, HI (United States) CCR Euratom, Ispra (Italy) Physics Dept., Univ. Milano (Italy) INFN, Milano (Italy) AT and T Bell Lab., Murray Hill, NJ (United States) Physics Dept., Univ. Pavia (Italy) INFN, Pavia (Italy) Physics Dept., Univ. Perugia (Italy) INFN, Perugia (Italy) Drexel Univ., Philadelphia, PA (United States) Charles Univ., Prague (Czechoslovakia) Czech Technical Univ., Prague (Czechoslovakia); Borex Collaboration

1992-05-01

Results of the three solar neutrino experiments presently running strongly suggest new neutrino physics scenarios to explain the discrepancy between the expected and measured neutrino flux. New experiments are needed to decide among the several theoretical explanations for this that has become known as the solar neutrino problem. This paper describes the unique features of the proposed low energy solar neutrino detector Borexino, that fully exploiting the powerful handless of liquid scintillation spectroscopy on large scale, will probe emerging suggestions on scenarios invoking neutrino mass mixing and magnetic moment. (orig.).

Uranium-scintillator device

International Nuclear Information System (INIS)

Smith, S.D.

1979-01-01

The calorimeter subgroup of the 1977 ISABELLE Summer Workshop strongly recommended investigation of the uranium-scintillator device because of its several attractive features: (1) increased resolution for hadronic energy, (2) fast time response, (3) high density (i.e., 16 cm of calorimeter per interaction length), and, in comparison with uranium--liquid argon detectors, (4) ease of construction, (5) simple electronics, and (6) lower cost. The AFM group at the CERN ISR became interested in such a calorimeter for substantially the same reasons, and in the fall of 1977 carried out tests on a uranium-scintillator (U-Sc) calorimeter with the same uranium plates used in their 1974 studies of the uranium--liquid argon (U-LA) calorimeter. The chief disadvantage of the scintillator test was that the uranium plates were too small to fully contain the hadronic showers. However, since the scintillator and liquid argon tests were made with the plates, direct comparison of the two types of devices could be made

Cherenkov and scintillation light separation in organic liquid scintillators

Energy Technology Data Exchange (ETDEWEB)

Caravaca, J.; Descamps, F.B.; Land, B.J.; Orebi Gann, G.D. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Yeh, M. [Brookhaven National Laboratory, Upton, NY (United States)

2017-12-15

The CHErenkov/Scintillation Separation experiment (CHESS) has been used to demonstrate the separation of Cherenkov and scintillation light in both linear alkylbenzene (LAB) and LAB with 2 g/L of PPO as a fluor (LAB/PPO). This is the first successful demonstration of Cherenkov light detection from the more challenging LAB/PPO cocktail and improves on previous results for LAB. A time resolution of 338 ± 12 ps FWHM results in an efficiency for identifying Cherenkov photons in LAB/PPO of 70 ± 3% and 63 ± 8% for time- and charge-based separation, respectively, with scintillation contamination of 36 ± 5% and 38 ± 4. LAB/PPO data is consistent with a rise time of τ{sub r} = 0.72 ± 0.33 ns. (orig.)

Cherenkov and scintillation light separation in organic liquid scintillators

International Nuclear Information System (INIS)

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

2017-01-01

The CHErenkov/Scintillation Separation experiment (CHESS) has been used to demonstrate the separation of Cherenkov and scintillation light in both linear alkylbenzene (LAB) and LAB with 2 g/L of PPO as a fluor (LAB/PPO). This is the first successful demonstration of Cherenkov light detection from the more challenging LAB/PPO cocktail and improves on previous results for LAB. A time resolution of 338 ± 12 ps FWHM results in an efficiency for identifying Cherenkov photons in LAB/PPO of 70 ± 3% and 63 ± 8% for time- and charge-based separation, respectively, with scintillation contamination of 36 ± 5% and 38 ± 4. LAB/PPO data is consistent with a rise time of τ r = 0.72 ± 0.33 ns. (orig.)

Saturation characteristics of liquid rare gas ionization chambers and recombination luminescence in liquid rare gas scintillation

International Nuclear Information System (INIS)

Takahashi, Tan; Konno, Satoshi; Kubota, Shinzo; Nakamoto, Jun; Miyajima, Mitsuhiro.

1978-01-01

From the saturation characteristics of liquid rare gases (Ar and Xe), the mean distance between electrons and ions. W-value, and the ratio of freely diffusion electrons were determined on the basis of the theory of Onsager. Their relationships with the scintillation due to recombination are also discussed. In the first part of this report, an analytic equation for the probability that an electron escapes from preferential recombination under the existence of an electric field is derived. The equation was then numerically solved with a computer code developed by Freeman. The adjusted parameters and the results of calculations for both Xe and Ar are presented together with the experimental results. Some discrepancy appeared between the analytical and the experimental results when the electric field was weak, and it is ascribable to the existence of the columnar (cluster) recombination and the effect of attachment due to the pulse method employed in the experiments. In the second part, the effect of electric field on the scintillation of liquid rare gases is considered, based on the theory of Onsager. (Aoki, K.)

A new value for the half-life of {sup 10}Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting

Energy Technology Data Exchange (ETDEWEB)

Korschinek, G., E-mail: Gunther.Korschinek@ph.tum.d [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Bergmaier, A. [Universitaet der Bundeswehr Muenchen, Fakultaet fuer Luft- und Raumfahrttechnik, Institut fuer Angewandte Physik und Messtechnik LRT2, Werner-Heisenberg-Weg 39, D-85577 Neubiberg (Germany); Faestermann, T. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Gerstmann, U.C. [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstaedter Landstr. 1, D-85764 Neuherberg (Germany); Knie, K.; Rugel, G. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Wallner, A. [VERA Laboratory, Faculty of Physics, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria); Dillmann, I. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Dollinger, G. [Universitaet der Bundeswehr Muenchen, Fakultaet fuer Luft- und Raumfahrttechnik, Institut fuer Angewandte Physik und Messtechnik LRT2, Werner-Heisenberg-Weg 39, D-85577 Neubiberg (Germany); Lierse von Gostomski, Ch. [Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, D-85748 Garching (Germany); Kossert, K. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Maiti, M.; Poutivtsev, M. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Remmert, A. [Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, D-85748 Garching (Germany)

2010-01-15

The importance of {sup 10}Be in different applications of accelerator mass spectrometry (AMS) is well-known. In this context the half-life of {sup 10}Be has a crucial impact, and an accurate and precise determination of the half-life is a prerequisite for many of the applications of {sup 10}Be in cosmic-ray and earth science research. Recently, the value of the {sup 10}Be 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 {sup 10}Be master solution was serially diluted with increasing well-known masses of {sup 9}Be. We then determined the initial {sup 10}Be concentration by least square fit to the series of measurements of the resultant {sup 10}Be/{sup 9}Be 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 {sup 10}Be/{sup 9}Be 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 {sup 10}Be concentration and activity yields a {sup 10}Be half-life of T{sub 1/2} = 1.388 +- 0.018 (1 s, 1.30%) Ma. In a parallel but independent study (Chmeleff et al. ), found a value of 1.386 +- 0.016 (1.15%) Ma. Our recommended weighted mean and mean standard error for the new value for {sup 10}Be half-life based on these two independent measurements is 1.387 +- 0.012 (0.87%) Ma.

Beta emitter radionuclides (90Sr contamination in animal feed: validation and application of a radiochemical method by ultra low level liquid scintillation counting

Directory of Open Access Journals (Sweden)

Marco Iammarino

2015-02-01

Full Text Available 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.

Determination of 129I using distillation method and liquid scintillation spectrometry

International Nuclear Information System (INIS)

Horvathova, B.; Dulanska, S.; Remenec, B.; Matel, L.; Gardonova, V.

2014-01-01

The conditions for effective distillation of iodine as a screening method for the determination of 129 I by liquid scintillation spectrometry were optimized. By distillation of iodine it is possible to achieve high-purity fraction without interferences needed for measuring 129 I for liquid scintillation spectrometer. Yields of separation were determined gravimetrically using PdI 2 ·H 2 O. The environment that was found to be effective for distillation of iodine is made up of 1 - 2 mol dm -3 HNO 3 together with 0.4 g of NaNO 2 as an oxidizing agent (I . →I 2 ). For testing of distillation, suitable apparatus for distillation of iodine was designed. The apparatus was connected to a vacuum box, which sucks iodine of the distilled solution. Then the iodine was captured in a solution of NaOH at a concentration of 1.5 mol dm -3 . As part of the optimization methodology, it was found that the concentration of NaOH solution for adsorption I 2 (g) does not have any influence on the yields, as opposed to its volume, where it is necessary to use a maximum amount of NaOH in the holding flask for maximum adsorption of iodine. It was determined, that time needed for coagulation PdI 2 ·H 2 O is 24 hours and suitable time for distillation was 20 minutes. Optimized method for the determination of 129 I was applied for various matrices from NPPs in Slovak Republic. Values of 129 I for all analyzed samples were less than the minimum detectable activity (0.043 Bq). The separation yields were in the range (73.14 to 82.04)% and 129 I was measured on a liquid scintillation spectrometer TRI CARB 2900TR with high detection efficiency of 95%. (authors)

A neutron multiplicity analysis method for uranium samples with liquid scintillators

Energy Technology Data Exchange (ETDEWEB)

Zhou, Hao, E-mail: zhouhao_ciae@126.com [China Institute of Atomic Energy, P.O.BOX 275-8, Beijing 102413 (China); Lin, Hongtao [Xi' an Reasearch Institute of High-tech, Xi' an, Shaanxi 710025 (China); Liu, Guorong; Li, Jinghuai; Liang, Qinglei; Zhao, Yonggang [China Institute of Atomic Energy, P.O.BOX 275-8, Beijing 102413 (China)

2015-10-11

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 {sup 252}Cf 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.

Calculation of the detection efficiency in liquid scintillators. II. Single positron emitters

International Nuclear Information System (INIS)

Grau Malonda, A.; Garcia Torano, E.

1982-01-01

Counting efficiency as a function of the figure of merit for 30 positron emitters has been computed from the positron energy spectrum. Only the efficiency contribution of positrons has been taken into consideration. The contribution of the annihilation photons depending on the volume of the scintillator will be investigated in a near future. Efficiency vs figure of merit is plotted and tabulated. (Author) 19 refs

Long wavelength scintillators for fiber-optic applications

International Nuclear Information System (INIS)

Lyons, P.B.; Franks, L.; Lutz, S.; Flournoy, J.; Fullman, E.

1980-01-01

The use of fiber optics in plasma diagnostics has spurred the development of long wavelength scintillators with fast temporal characteristics. In this paper we describe several new liquid scintillator systems with fluorescent emissions maxima up to 730 nm. Subnanosecond scintillator FWHM response times have been obtained by the operation of liquid scintillators at elevated temperatures. Data on fiber system sensitivity versus fiber length and scintillator emission wavelength will be presented

Estimating the standard deviation for 222Rn scintillation counting - a note concerning the paper by Sarmiento et al

International Nuclear Information System (INIS)

Key, R.M.

1977-01-01

In a recent report Sarmiento et al.(1976) presented a method for estimating the statistical error associated with 222 Rn scintillation counting. Because of certain approximations, the method is less accurate than that of an earlier work by Lucas and Woodward (1964). The Sarmiento method and the Lucas method are compared, and the magnitude of errors incurred using the approximations are determined. For counting times greater than 300 minutes, the disadvantage of the slight inaccuracies of the Sarmiento method are outweighed by the advantage of easier calculation. (Auth.)

Determination of low α activity levels applying a pulse discrimination system to a conventional liquid scintillation unit

International Nuclear Information System (INIS)

Oliveira, A.A.; Bonino, A.D.

1983-01-01

The described system allows the measurement of α activity in the presence of β/γ activities in various types of samples. Pulse shape discrimination of the signal from a conventional liquid scintillation unit is used for assessing the α activity in samples obtained from several radiochemical processes as well as in samples from area and surface monitoring, without separating for the γ and β emitters present. Additionally, the considerable background reduction attained by this method makes possible the utilization of automatic liquid scintillation systems for measuring enviromental and occupational monitoring samples. (Author) [es