Measurement of the Background Level in the Spectra of Internal-Conversion Electrons Using the МАС-1 Microscope Complex

Abstract

A method for measuring the spectral lines in an Р-50 photoemulsion plate with a varying background level is described. The β-ray spectrograph of the Joint Institute for Nuclear Research's Laboratory of Nuclear Problems, was used to record the spectra. The plate was exposed to internal-conversion electrons produced by the decay of erbium isotopes (erbium fraction). The spectral measurements were performed using the МАС-1 microscope complex. The distribution of the background level over the plate surface was measured. Using the L-structure of the γ-ray line of 161Ho with an energy of 175.5 keV as an example, it was shown that the accuracy of the intensity measurements was 10% or better. The accuracy in measuring the background level governed the accuracy in identifying the multipolarity of nuclear γ transitions. A precision TV system for data readout based on a 768 × 576 pixel CCD matrix provided a measurement accuracy of 0.5 μm for both coordinates.