M C Joshi
Articles written in Proceedings – Section A
Volume 38 Issue 5 November 1953 pp 367-375
An electrostatic beta-ray spectrometer using a spherical condenser has been constructed for study of weak sources, and its performance has been tested with accelerated electron beams. The device, which is intended for low energy range of electrons, has, for the slit system employed, the resolving power of 1·6% with transmission 1/44 of a sphere which compares favourably with that in other types of spectrometer. The electron energy E (in KeV) focussed is 4·37 times the voltage V. in K.V. on the electrodes.
Volume 43 Issue 5 May 1956 pp 255-264
A technique for studying short-lived radio-activities is described. It is suitable for half-lives in the range from a second to several minutes. The activity is induced at one point in the sample spread over a moving, endless conveyor belt and is studied at another point. The equilibrium counting rate then depends on the speed of the belt. The activity of 22 sec. Ag110 and that of 2·3 min. Ag108 have been studied. The maximum energies of beta-ray groups were determined from absorption curves. Gamma-ray energies were obtained with a scintillation spectrometer. It is shown that in favourable cases, when two short-lived activities are present, the shorter-lived one can be filtered out by adjusting the speed of the belt.
The authors believe that the technique can easily be adapted to an experiment where irradiation is obtained by means of a reactor and can be of great value when making detailed investigation of radiations from short-lived isotopes.
Volume 45 Issue 6 June 1957 pp 390-401
Radiations emitted in the decay of Samarium-153 have been studied in the Siegbahn-Slätis
Volume 49 Issue 6 June 1959 pp 322-325
An experimental set up is described for converting longitudinal polarisation of beta particles to transverse polarisation and for determining the degree of polarisation, using the method of Mott scattering from a thin gold foil. Electron polarisation in the energy range 90 to 150 KeV can be studied. The degree of polarisation for beta particles of energy 110 KeV from Co60, Pr144 and Rb86 has been determined and is seen to be equal to — V/C, within the limits of experimental error.
Volume 50 Issue 5 November 1959 pp 342-348
Decay of Eu155 has been studied using intermediate image
Volume 52 Issue 4 October 1960 pp 157-164
Decay of 15 days activity of Eu156 has been studied using intermediate image β-ray spectrometer and β-γ, β-ē and γ-γ coincidence techniques. The β-groups, β1 = 2450 Kev., β2 = 1180 Kev., β3
Volume 73 Issue 6 June 1971 pp 297-305