Applications of Beta Ray Spectroscopy

Author: Hornyak, William Frank

Year: 1949

Degree: Dissertation (Ph.D.)

Advisor: Lauritsen, Thomas

Committee Member: Unknown, Unknown

Option: Physics; Electrical Engineering

DOI: 10.7907/q8cc-6160

Abstract

The design procedure is discussed for the construction of a lens type beta ray spectrometer having a large solid angle and capable of focusing electrons with energies up to 20 Mev. The observed performance of the instrument is compared with theory.

The application of beta ray spectroscopy to the energy determination of -f-rays by use of both the photoelectric and Compton effects is considered. The effects of converter thickness and finite instrumental resolution are treated extensively. The analysis of the experimental data, employing these techniques, leads to the determination of excited states in Li7 at 476.7 ± 0.9 Kev; B10 at 713.8 .± 1.3 Kev; Ni60 at 1172.4 .±- 1.8 and 1330. 9 ± 2.1 Kev; and c13 at 30.92. ±. 12 Kev.

The continuous beta spectra from the radioactive elements Li8, B12, and N13 were studied. The upper energy limits for these spectra were determined as 15.8 ± 0.1 Mev, 13.43 ± 0.06 Mev, and 1.202 ± .005 Mev respectively. Experimental evidence is given to show that the beta decay of Li8 proceeds mainly to a broad excited state at ≃ 3 Mev, the transitions to the ground state being estimated at less than 2 percent. Evidence for possible highly excited states in Be8 and C12 is presented and discussed.

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