DECAY OF A NEW ISOTOPE, S$sup 3$$sup 0$

Journal Article · Mon May 01 00:00:00 EDT 1961 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.122.879· OSTI ID:4031962

Robins, E L; Rhode, J I; Johnson, O E

Scintillation techniques were used to study the beta and gamma radiation from high-purity natural silicon targets after irradiation with 8-Mev He>s3/sup / ns. In addition to activities associated with well-known radioisotopes, an activity with a (1.35 plus or minus 0.10)-sec half-life was observed. A (677 plus or minus 10)-kev gamma ray was associated with the 1.35sec half-life. Decomposition of decay curves constructed from data obtained by observing annihilation radiation revealed a component with the same half life. Half-life measurements using positrons with energies in excess of 3.15 Mev also indicated the presence of a 1.35-sec activity. The beta spectrum in coincidence with two annihilation quanta extended to approx equal 5.0 Mev, a higher energy than can be accounted for by positrons from the known reaction products. The beta spectrum in coincidence with the (677 plus or minus 10)-kev gamma ray had an end-point energy of (4.30 plus or minus 0.15) Mev. The assignment of the (1.35 plus or minus 0.10)sec activity to the decay of S>s3/sup > /oduced in the reaction Si>s2/sup >(/>s3/sup ,/S>s3/sup >,/nd the proposed decay scheme are supported by arguments formulated from the known characteristics of reaction products, half-life studies using both beta and gamma radiation, the features of the experimental beta and gamma spectra, beta-gamma coincidence spectra, nuclear systematics, and nuclear theory. The decay of the ground state of S>s3/sup > / kes place by at least two positron transitions: beta /sub 1/, a (4.98 plus or minus 0.15)-Mev superallowed transition to the 1+, T = 0 ground state of P>s3/ sup >;/bb/sub 2/, a (4.30 plus or minus 0.15)-Mev superallowed transition to the O+, T = 1 (0.677 plus or minus 0.010)Mev first excited state of P>s3/sup >,/ o evidence was found for beta /sub 3/, presumably an allowed transition to the 1+, (0.704 plus or minus 0.005)-Mev second excited state of P>s3/sup >,/ut an experimental upper limit of 25% is placed on its branching percentage. Branching percentages of (19 plus or minus 2)%, (73 plus or minus 7)%, and (8 plus or minus 10)% for beta /sub 1/, beta /sub 2/, and beta /sub 3/ were calculated using the measured S>s3/sup >/ 0/sup / half-life, a S>s3/sup >-/s3/sup > /ss difference of (6.01 plus or minus 0.15) Mev, assumed charge independence of nuclear forces, and the fact that log ft for 0>s+/sup / 0>s+/sup /sitrons within T = 1 charge multiplets is almost constant. (auth)

• Research Organization: Purdue Univ., Lafayette, Ind.
• NSA Number: NSA-15-017602
• OSTI ID: 4031962
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Vol. Vol: 122; Other Information: Orig. Receipt Date: 31-DEC-61
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

PHYSICS
ANNIHILATION
BETA DECAY
BETA DETECTION
BETA SPECTROMETERS
BRANCHING RATIO
COINCIDENCE METHODS
DECAY
EFFICIENCY
ELECTRIC CHARGES
ENERGY LEVELS
ENERGY RANGE
EXCITATION
GAMMA DETECTION
GAMMA RADIATION
GAMMA SPECTROMETERS
HALF-LIFE
HELIUM 3
INTERACTIONS
ION BEAMS
IRRADIATION
ISOSPIN
MASS
MATHEMATICS
MEASURED VALUES
NEUTRONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEAR THEORY
NUCLEI
NUMERICALS
PARITY
PARTICLE MODELS
PHOSPHORUS 30
POSITRONS
RADIOACTIVITY
SCINTILLATION COUNTERS
SILICON
SILICON 28
SPECTRA
SPIN
SULFUR 30
TARGETS