LIFETIMES OF EXCITED NUCLEAR STATES USING DELAYED REACTION GAMMA RAYS

Technical Report · Mon Oct 29 04:00:00 EST 1962

OSTI ID:4760478

Bauer, R W; Anderson, J D; Christensen, L J

Using the pulsed charged-particle beam from the Livermore variable- energy cyclotron, the delayed reaction gamma rays were employed for a direct measurement of lifetime of excited nuclear states in the nanosecond region. This technique is particularly useful in the investigation of states not populated (or only weakly populated) by radioactive decay. The mean lives of excited states of several nuclei in the f/sub 7/2/ shell were measured. Using the Ti/sup 48/(p,n gamma ) and Sc/sup 45/( alpha ,n gamma ) reactions the 305-kev state of V/sup 48/ yields (10/9 plus or minus 0/4) nsec. Using the V/sup 51/(p,n gamma ) and Ti/ slup 48/( alpha ,n gamma ) reactions the 750-kev state of Cr/sup 51/ yields (10.8 plus or minus 0.5) nsec. Considering previously reported level spin and gamma- ray multipolarity assignments, these lifetimes appear to be anomalously long, indicating an extremely high degree of retardation of these electromagnetic transitions within the f/sub 7/2/ neutron and proton shells. These measurements were confirmed using the delayed gamma-gamma coincidences foliowing the radioactive decays of Cr/sup 48/ and Mn/sup 51/, respectively. (auth)

• Research Organization: California. Univ., Livermore. Lawrence Radiation Lab.
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-17-006958
• OSTI ID: 4760478
• Report Number(s): UCRL-7091
• Country of Publication: United States
• Language: English

Related Subjects

ALPHA PARTICLES
BEAMS
CHROMIUM 48
CHROMIUM 51
COINCIDENCE METHODS
CYCLOTRONS
DECAY
ENERGY LEVELS
EXCITATION
GAMMA RADIATION
LIFETIME
MANGANESE 51
MEASURED VALUES
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
PHYSICS
PROTONS
SCANDIUM 45
SPIN
TITANIUM 48
VANADIUM 48
VANADIUM 51