[en] In this paper, liquid scintillation counting efficiency v.s. a free parameter for E.C. and gamma-ray emitters has been computed. It is assumed that the decay scheme has only a gamma transition coincident with the E.C. Internal-conversion electrons or gamma photons may be emitted. The evaluation has been carried out for three different volumes, 5, 10 and 15 ml, of two scintillators, a toluene and INSTAGEL, and thirteen radionuclides: 7Be, 51cr, 54Mn, 81Kr, 110Sn, 119Sb, 125I, 139Ce, 143Pm, 145Sm, 152Dy, 159Dy, 166Yb. (Author) 16 refs

[en] Due to hypothetical Loretz invariance violation, additional terms arise in the differential rate for neutrino radiation accompanying electron capture by polarized nuclei. These terms, as well as the parity-violating term, can be probed by measurement of a small recoil force acting on a radioactive sample. An expression for this force is obtained for the case of allowed Gamow–Teller transitions. We discuss prospects to measure the force by using the methods of the magnetic resonance force microscopy, present a list of the most suitable isotopes and give the numerical estimates for mass and activity of required radioactive samples. (paper)

[en] A new experimental run of searching for EC/EC decay of "1"0"6Cd was performed at the Modane underground laboratory (4800 m w.e.) using the TGV-2 spectrometer and ∼23.2 g "1"0"6Cd with enrichment of 99.57%. The limit on 2νEC/EC decay of "1"0"6Cd - T_1_/_2(2νEC/EC) > 3.1×10"2"0 y, at 90% C.L was obtained from the preliminary calculation of experimental data accumulated for 7018 h of measurement. The limits on the resonance neutrino-less double electron capture decay of "1"0"6Cd were obtained from the measurement of ∼23.2 g of "1"0"6Cd with the low-background HPGe spectrometer OBELIX lasted 395 h - T_1_/_2(KL, 2741 keV) > 0.9×10"2"0 y and T_1_/_2(KK, 2718 keV) > 1.4×10"2"0 y at 90% C.L

[en] An improvement of the statistical and systematic uncertainty beyond the level achieved in GALLEX is an essential prerequisite for GNO. As major contributions to these errors are associated with the detection of the EC-decay of ⁷¹Ge in miniaturized gas counters, low-temperature calorimetric detectors (LTCs) might provide a promising alternative for a later phase of GNO. We report the status of our R and D project on optimization of LTCs for this application

[en] This paper gives a review of the development of the triple-to-double coincidence ratio (TDCR) method for standardizing pure β- and pure electron capture (EC)-radionuclides. The initial idea of Schwerdtel and practical realization and elaboration of the TDCR method by Pochwalski is presented. The main aspects and theoretical principle of the method are summarized and progress on the development of the theoretical model is presented. The details of the activity determination of pure β- and pure EC radionuclides are discussed, along with specific details in the application of the method in each case. The enhanced TDCR method based on the MAC3 electronic system developed in France is also discussed. Different applications of the TDCR method in metrology laboratories around the world are also pointed out

[en] Theoretically determined electron-capture detector (ECD) characteristics, showing the dependences of the ionization current and the relative detector signal on the concentration of investigated molecules, are presented. Calculations take into account the influence of the parameters of the pulsed supply, of the type and purity of the carrier gas, of the activity of the radiation source and of the detector electrode geometry on the characteristics presented. For concentration characteristics, the given equations take into account the physical properties of the investigated particles, described by a constant (k₁). The general equation describing the detector ionization current derived in this paper includes the empirical equation of Scolnick and the equation of Lovelock et al. The mathematical analysis carried out enables one to determine the minimum detectability for a signal deviating by delta from the linear signal of the ECD. (Auth.)

[en] In this paper, counting efficiency vs figure of merit for 19 electron capture radionuclides has been computed. Toluene based s c i n t i l l a t o r solution of 15 cm³ has been assumed in the computation. The relationships to obtain the probability per decay are given and the computed efficiency tabulated.(Author)

[en] The implementation of CIEMAT-NIST calibration method for radionuclides which decay by electron capture or pure beta emission was made in 1999 at LNMRI, commissioned by INMETRO from 1989, using a co-operation of CIEMAT Laboratory of Spain and the liquid scintillation counter 1414 model of LBK-WALLAC. The performance was demonstrated with the activity determination of the following radionuclides: two pure beta emitters, ¹⁴ C and ⁹⁰ Sr; one pure electron capture, ⁵⁵ Fe; one electron capture and beta emitter, ²⁰⁴ Tl; and one beta-gamma emitter, ⁶⁰ Co. With these radionuclides was possible to analyze the method, the system and measurement conditions in a wide energy range. To assure the success of implementation and the metrologic traceability, comparisons were made with reference values of solutions calibrated at CIEMAT. Moreover, solutions of ²⁰⁴ Tl and ⁶⁰ Co were also calibrated and compared with BIPM and LNMRI reference values, respectively. (author)

[en] In this paper, liquid scintillation counting efficiency v.s. a free parameter for E.C. and gamma-ray emitters has been computed. It is assumed that the decay scheme has only a gamma transition coincident with the E.C. Internal-conversion electrons of gamma photons may be emitted. The evaluation has been carried out for three different volumes, 5, 10 and 15 ml, of two scintillators, toluene and INSTAGEL, and thirteen radionuclides: ⁷Be, ⁵¹Cr, ⁵⁴Mn, ⁸¹Kr, ¹¹⁰Sn, ¹¹⁹Sb, ¹²⁵I, ¹³⁹Ce, ¹⁴³Pm, ¹⁴⁵Sm, ¹⁵²Dy, ¹⁵⁹Dy, ¹⁶⁶Yb. (Author)

[en] Short communication