LOW ENERGY NUCLEAR PHYSICS. Progress Report, June 1, 1962 to May 31, 1963

Technical Report · Fri Mar 01 00:00:00 EST 1963

OSTI ID:4720554

Roy, R R

Status of the 5.5-Mev Van de Graaff generator and the puise height analyzer and vaccum evaporator to be used with it are reported. Research to be undertaken at the facility is also described. Total absorption coefficients for neutron-capture gamma rays of 5.4, 6.4, 7.7, and 10.8Mev were measured for the elements Be, Al, Cu, Sn, and Pb. Angular distributions of 1.37-Mev gamma rays from the Mg/sup 24/(n,n' gamma )Mg/sup 24/ reaction and of the 0.85-Mev gamma rays from Fe/sup 56/(n,n' gamma ) reactions were measured and found to agree with Satchler's theory. Circuitry giving good discrimination against gamma pulses produced in a stilbene crystal was constructed. Using previously discussed methods, the cross sections for the Li/sup 7/( gamma ,n)Li/sup 6/ and the B/sup 10/ ( gamma ,n)B/sup 9/ reactions at energies around 10 Mev were measured. Study of the Se/sup 81/ decay scheme revealed gamma rays of 827. 647, 565, 545, 428, and 180 kev. The data also indicate Br/sup 81/ states at 827, 647, 565, 428, and 282 kev. Investigation of the Ba/sup 139/ decay scheme indicated gamma rays of 0.166, 1.25, and 1.41 Mev; but gave no evidence for 0.28, 0.50, 0.78, 0.95, or 1.09 Mev rays. A weak 0.84Mev gamma ray was noted, and some interesting gamma - gamma and gamma -x ray coincidences were observed. Evidence was also found for a 0.134-Mev transition. A crossover gamma ray of low intensity between the 1420- kev level and the In/sup 115/ ground state was indicated for the Cd/sup 115/ decay scheme. An unsuccessful search for an Os/sup 187/ isomeric state was made. Gamma-gamma coincidence studies of the decay of 24-hr W/sup 187/ were completed. Research currently in progress includes examination of double-quantum deexcitation of nuclei; of the triple cascade in Zn/sup 71/ decay; of the (n, alpha ) cross section in Sm /sup 49/, Gd/sup 155/, and Gd/sup 157/; of the neutron fission of Th/sup 232/; of (n, alpha ) and (n,p) reactions initiated by reactor neutrons, and of photofission and ( gamma ,n) reactions in Th/sup 232/ and U/sup 238/. Theoretical work dealt with neutral and scalar theory with recoil, triplet production in H, the Levinson theorem in soluble models of field theory, model field theories, photoproduction of above 400 deg C mesons on deuterons, retardation effects in deuteron photodisintegration, Regge trajectories for n-n scattering systems, sensitivity of nuclear matter parameters to the two-body potential, p-p scattering at 650 Mev, and the theory of (d, gamma ) reactions. Abstracts of 13 papers submitted for publication during 1962-1963 are included, and references to 11 other papers that appeared since the last report are given. (D.C.W.)

• Research Organization: Pennsylvania State Univ., University Park. Coll. of Chemistry and Physics
• DOE Contract Number: AT(30-1)2399
• NSA Number: NSA-17-020564
• OSTI ID: 4720554
• Report Number(s): TID-18442
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-63
• Country of Publication: United States
• Language: English

Related Subjects

PHYSICS
ABSORPTION
ALPHA PARTICLES
ALUMINUM
ANGULAR DISTRIBUTION
BARIUM 139
BERYLLIUM
BORON 10
BORON 9
BROMINE 81
CADMIUM 115
CAPTURE
CIRCUITS
COINCIDENCE METHODS
COPPER
CROSS SECTIONS
CRYSTALS
DECAY
DEUTERONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
ENERGY LEVELS
ENERGY RANGE
EVAPORATION
EXCITATION
FIELD THEORY
FISSION
GADOLINIUM 155
GADOLINIUM 157
GAMMA RADIATION
HYDROGEN
INDIUM 115
IRON 56
KAONS
KEV RANGE
LEAD
LEVINSON THEOREM
LITHIUM 6
LITHIUM 7
MAGNESIUM 24
MEASURED VALUES
MEV RANGE
NEUTRONS
NUCLEAR REACTIONS
OSMIUM 187
PHOTOFISSION
PHOTOPRODUCTION
PLANNING
PROTONS
PULSE ANALYZERS
PULSES
RECOILS
RE