Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei
- Lawrence Berkeley National Lab., CA (United States). Nuclear Science Div.
To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of 31Cl, 27P and 28P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas ΔE-gas ΔE-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in 31Cl and 27P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of 31Cl were shown to be from the decay of 25Si. In 27P, two proton groups at 459 ± 14 keV and 610 ± 11 keV, with intensities of 7 ± 3% and 92 ± 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the β-decay of 28P, at 1,444 ± 12 keV with a 1.7 ± 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, 17Ne and 33Ar, were studied. A new proton group with energy 729 ± 15 keV was observed following the beta-decay of 17Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from 17Ne and 33Ar were resolved.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 286266
- Report Number(s):
- LBNL-38848; ON: DE96012908; TRN: 96:023269
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: Mar 1996
- Country of Publication:
- United States
- Language:
- English
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Additional Results from the Beta-delayed Proton Decays of {sup27}P and {sup 31}Cl
Improvements to the on-line mass separator, RAMA
Related Subjects
CHLORINE 37
PROTON-EMISSION DECAY
PHOSPHORUS 27
PHOSPHORUS 28
NEON 17
ARGON 33
HELIUM
SILICON 25
BETA DECAY
TARGET CHAMBERS
BEAM OPTICS
CHARGED PARTICLE DETECTION
RADIATION DETECTORS
ISOTOPE SEPARATORS
ALPHA DECAY
DAUGHTER PRODUCTS
REACTION PRODUCT TRANSPORT SYSTEMS
GAMOW-TELLER RULES
DELAYED ALPHA PARTICLES
DELAYED PROTONS
ACCELERATOR FACILITIES