An improved method for the measurement of fine effects in electron spectra

Search for an admixture of heavy neutrinos in the beta-decay of241Pu

“…The spectra are taken by point-by-point sweeping many times over the required energy interval with the exposure time of 1 s per point in each sweep. In order to provide high reproducibility of the energy scale during long-term measurements lasting sometimes several months, we have introduced an improved method of data acquisition and evaluation [18]. We measure actual voltages on the electrostatic analyser each second and store these voltages together with the counting rates in a computer memory.…”

“…(iv) The 241 Pu β-decay does not lead to a stable daughter nucleus. Due to the long half-life of 241 Am (T 1/2 = 432 y) the correction of the investigated β-spectrum for conversion and Examples of the electron spectra taken with the electrostatic spectrometer [16,18]. These are the original spectra corrected only for very rare outliers (section 4.1).…”

“…Using the electrostatic spectrometer [16,18] we measured the lower part of the 241 Pu βspectrum from almost zero up to 9 keV, where the electron energy losses play a dominant role. We investigate whether our method for calculation of the losses, that is based on individual elastic and inelastic scattering, is applicable even at keV energies.…”

Erratum to: “Development of a Super-Stable Datum Point for Monitoring the Energy Scale of Electron Spectrometers in the Energy Range up to 20 keV” by D. Vénos, M. Zbořil, J. Kašpar, O. Dragoun, J. Bonn, A. Kovalík, O. Lebeda, N. A. Lebedev, M. Ryšavý, K. Schlösser, A. Špalek, and Ch. Weinheimer, Vol. 53, No. 3, pp. 305–312, July, 2010

“…The natural width of such a peak is determined by the natural widths of the corresponding atomic level and nuclear transition. In our investigations, we employed two different types of electron spectrometers: the differential electrostatic ESA12 [21,22] of the cylindrical-mirror type with second-order focusing, supplied with a retarding (accelerating) lens and a channel multiplier as an electron detector (Institute of Nuclear Physics, Academy of Sciences of the Czech Republic, Ř ež near Prague), and an integral spectrometer [23] with the magnetic adiabatic collimator with an electrostatic filter type -the MAC-E-Filter (Institute of Physics, University of Mainz, Germany). The first of the spectrometers operates in the 0-20 keV range with a relative instrument resolution ΔE/E= 0.011 in the "basic" mode and with an absolute resolution ΔE = 1 and 3 eV for electron energies of 2 keV and 7 keV, respectively, in the electron retardation mode (reduced transmission).…”

Constraints on the Active and Sterile Neutrino Masses from Beta-Ray Spectra: Past, Present and Future1

“…The KLL-Auger lines of carbon and oxygen superimposed on continuous β-spectra of 241 Pu and 63 Ni [214]. The spectra of the vacuum-evaporated sources were recorded with an electrostatic spectrometer [210], [215] by scanning the shown energy regions 10 000 and 18 000 times 24 . The measurement time was 1 s per point in every scan.…”