A system to measure isomeric state half-lives in the 10 ns to 10 μs range

Journal Article · Tue Jul 15 00:00:00 EDT 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4886814· OSTI ID:22308674

Allegro, P. R. P.; Medina, N. H.; Oliveira, J. R. B.; Cybulska, E. W.; Seale, W. A.; Ribas, R. V. ^[1]; Linares, R. ^[2]; Silveira, M. A. G. ^[3]

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1. Institute of Physics, University of São Paulo, C.P. 66318, 05315-970 São Paulo, São Paulo (Brazil)
2. Fluminense Federal University, 24220-900 Niterói, Rio de Janeiro (Brazil)
3. Universitary Center of FEI, 09850-901 São Bernardo do Campo, São Paulo (Brazil)

The Isomeric State Measurement System (SISMEI) was developed to search for isomeric nuclear states produced by fusion-evaporation reactions. The SISMEI consists of 10 plastic phoswich telescopes, two lead shields, one NaI(Tl) scintillation detector, two Compton suppressed HPGe γ-ray detectors, and a cone with a recoil product catcher. The new system was tested at the 8 UD Pelletron tandem accelerator of the University of São Paulo with the measurement of two known isomeric states: {sup 54}Fe, 10{sup +} state (E = 6527.1 (11) keV, T{sub 1/2} = 364(7) ns) and the 5/2{sup +} state of {sup 19}F (E = 197.143 (4) keV, T{sub 1/2} = 89.3 (10) ns). The results indicate that the system is capable of identifying delayed transitions, of measuring isomeric state lifetimes, and of identifying the feeding transitions of the isomeric state through the delayed γ-γ coincidence method. The measured half-life for the 10{sup +} state was T{sub 1/2} = 365(14) ns and for the 5/2{sup +} state, 100(36) ns.

• OSTI ID: 22308674
• Journal Information: Review of Scientific Instruments, Vol. 85, Issue 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
COINCIDENCE METHODS
COMPTON EFFECT
FLUORINE 19
GAMMA DETECTION
HALF-LIFE
HIGH-PURITY GE DETECTORS
IRON 54
ISOMERIC NUCLEI
KEV RANGE
LEAD
NAI DETECTORS
PELLETRON ACCELERATORS
RECOILS
SHIELDS
TANDEM ELECTROSTATIC ACCELERATORS
TELESCOPES
THERMONUCLEAR REACTIONS