Decay studies of nuclei near the proton drip line: /sup 35/Ca, /sup 31/Ar, /sup 69/Br, /sup 65/As

Technical Report · Thu Jun 01 00:00:00 EDT 1989

DOI:https://doi.org/10.2172/5918746· OSTI ID:5918746

Reiff, J E

Studies of new beta-delayed two-proton emitters and a search for ground state proton radioactivity in medium mass nuclei were performed using various experimental techniques in conjunction with several detection systems. A helium-jet transport system and three-element silicon telescopes were used to discover the existence and detect the decay of the first T/sub Z/ = /minus/5/2 nuclide, /sup 35/Ca. Two-proton emission from the T = 5/2 isobaric analog state in /sup 35/K at an excitation energy of 9.053 /plus minus/ 0.045 MeV, fed by the superallowed beta decay of /sup 35/Ca, resulted in transitions to both the ground state and first excited state of /sup 33/Cl. The corresponding two-proton sum energies were 4.089 /plus minus/ 0.030 MeV and 3.287 /plus minus/ 0.030 MeV. Measurements of the individual proton energies indicated the prevalence of a sequential decay mechanism. Using the isobaric multiplet mass equation, the mass excess of /sup 35/Ca was calculated to be 4.453 /plus minus/ 0.060 MeV. In order to study whose half-lives were too short for the helium-jet system, an in-beam recoil catcher wheel was constructed. The wheel speed can be varied to study nuclides whose half-lives range from 100 /mu/s to /approximately/250 ms. The first new decay observed with the wheel system and traditional /Delta/E-E telescopes was the beta-delayed two-proton emission from /sup 31/Ar. The two-proton sum energy of /approximately/7.5 MeV corresponds to a transition from the isobaric analog state in /sup 31/Cl to the ground state of /sup 29/P. The search for proton radioactivity required the development of low energy, particle identification detector telescopes. These telescopes, comprised of a gas /Delta/E and silicon E, were used in conjunction with the in-beam recoil catcher wheel to search for ground state proton emission from /sup 69/Br and /sup 65/As. 90 refs., 24 figs., 8 tabs.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5918746
• Report Number(s): LBL-27387; ON: DE89015342
• Resource Relation: Other Information: Thesis (Ph.D.). Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ARGON 31
BETA DECAY
ARSENIC 66
BROMINE 69
CALCIUM 35
DATA ACQUISITION SYSTEMS
DETECTION
LIGHT NUCLEI
TRANSITION AMPLITUDES
ALKALINE EARTH ISOTOPES
AMPLITUDES
ARGON ISOTOPES
ARSENIC ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BROMINE ISOTOPES
CALCIUM ISOTOPES
DECAY
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPES
MILLISEC LIVING RADIOISOTOPES
NUCLEAR DECAY
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
RADIOISOTOPES
651520* - Nuclear Properties & Reactions
A=39-58
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651620 - Nuclear Properties & Reactions
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