A method for determination of the 152Eu activity

Activity measurement of mixed complex radionuclide like 152Eu with different methods

¹⁵²Eu has been standardized by three independent 4π β-γ coincidence counting systems with beta detectors as proportional counter, plastic scintillator and liquid scintillator along with the CIEMAT/NIST method. The average activity concentration by primary methods was linked to key comparison reference value (KCRV) by comparing it with that of 4π γ ionization chamber (GIC) whose calibration factor was determined from the KCRV (BIPM.RI(II)-K1.Eu-152 and CCRI(II)-K2.Eu-152) and deviates from GIC by ± 0.16% indicating good agreement within standard uncertainties.

A simple and versatile data acquisition system for software coincidence and pulse-height discrimination in 4πβ-γ coincidence experiments

A simple but versatile data acquisition system for software coincidence experiments is described, in which any time stamping and live time controller are not provided. Signals from β- and γ-channels are fed to separately two fast ADCs (16 bits, 25 MHz clock maximum) via variable delay circuits and pulse-height stretchers, and also to pulse-height discriminators. The discriminating level was set to just above the electronic noise. Two ADCs were controlled with a common clock signal, and triggered simultaneously by the logic OR pulses from both discriminators. Paired digital signals for each sampling were sent to buffer memories connected to main PC with a FIFO (First-In, First-Out) pipe via USB. After data acquisition in list mode, various processing including pulse-height analyses was performed using MS-Excel (version 2007 and later). The usefulness of this system was demonstrated for 4πβ(PS)-4πγ coincidence measurements of (60)Co, (134)Cs and (152)Eu. Possibilities of other extended applications will be touched upon.

Standardization of 152Eu and 154Eu by 4πβ−4πγ coincidence method and 4π(β+γ) integral counting

The 4pibeta-4pigamma coincidence counting and 4pi(beta+gamma) integral counting techniques were applied for the standardization of 152Eu and 154Eu. In these techniques, the beta-detector is composed of two thin plastic scintillators sandwiching the source coupled with a slender photomultiplier tube. This beta-detector was inserted into a large well-type NaI(Tl) scintillation detector for gamma-ray detection, making a 4pibeta-4pigamma detector configuration. The results obtained by the above two techniques were in good agreement and consistent with the results of international comparisons.

Absolute determination of activity per mass and half-life measurements of 152Eu

A solution of 152Eu was absolutely standardized by the 4pi beta (PPC)-gamma (HPGe) coincidence counting method as part of an intercomparison program coordinated by Bureau International des Poids et Mesures. The measured activity has been used to determine the calibration factor of the LNMRI reference ionization chamber for 152Eu. The half-life of 152Eu was also determined by means of a 4pi gamma ionization chamber to be (4963.6+/-15.3) days, and compared with others published values.

Methods of producing radionuclides for spectrometric gamma-ray sources and their standardization--2. Europium-152

The radionuclide 152Eu was produced by irradiating 151Eu2O3 or 151EuCl3 enriched to 98.9% with thermal neutrons. 152Eu was separated from rare-earth impurities by extraction chromatography on a column using 0.6 M nitric acid eluent. The specific activity of the 152Eu was 1-10 Ci/g of Eu. The impurity of the 154Eu did not exceed 0.1%. The activity standardization of 152Eu was carried out by extrapolation of 4 pi (beta, e, x)-gamma coincidences. The relative gamma-ray intensities for 28 gamma-ray energies emitted in 152Eu decay have been measured.