PHYSICS DIVISION PROGRESS REPORT FOR JANUARY 1, 1958 TO MARCH 31, 1958

Technical Report · Fri Oct 31 00:00:00 EST 1958

OSTI ID:4333524

Additional studies were made of the effect of time reversal on neutron beta decay using iron polarizers. Calculations by R. L. Sears indicate the He/ sup 3/( alpha , gamma )Be/sup 7/ reaction now predominates in the central regions of the sun. Possible decay modes far the Be/sup 7/ under solar conditions are discussed. A method for standardizing S/sup 35/ is described. The method is based on a comparison of LiS/sup 35/O/sub 4/-NbCl/sub 3/ and LiSO/sub 4/-Nb/sup 95/Cl/sub 3/ solutions . A spray technique was used to prepare very thin, uniform sources of Na/sup 22/, Na/sup 24/, and Co/sup 60/. The measured efficiency of a 4 pi BETA counter-source combination using these sources is reported. Methods used in calibrating the energy sensitivity of a 5-in. thick by 7-in. diameter plastic scintillator to be used in 14-Mev neutron scattering studies are described. Thermal neutron flux and cadimium ratio distribution measurements were made in two longitudinal and two transverse holes of NRU. Nonisotropic neutron angular distributions from U/sup 236/ and Cf/sup 252/ are reported. The properties of the energy levels in O/sup 18/ from the C/sup 14/( alpha , gamma ) reaction are discussed. the linear polarization of 1.64 Mev gamma rays from the C/sup 12/(He/sup 3/,p gamma )N/sup 14/ reaction and the 0.94 and 1.08 Mev gamma rays from the O/sup 16/(He/sup 3/,p gamma )F/sup 18/ reaction was studied using 2.0 and 2.96 Mev He/sup 3/ ions. An analysis was made of the gamma ray coincidence spectra from the reaction Be/sup 9/(He/sup 3/,p gamma )B/sup 11/. Pronounced resonance structure was observed in the excitation curves for the proton groups to the F/sup 18/ states and far the alpha group to the ground state of O/sup 15/ in O/sup 16/(He/sup 3/) reactions. A search for non-resonant alpha capture in N/sup 14/ was made in an effort to explain discrepancies in the calculated and observed angular distribations of the 2.54 Mev gamma rays. A further measurement of the change in energy of neutrons scattered from liquid helium gave Q = 0.86 A/sup -1/ and E = 13.1 deg K. A list of gamma rays energies and intensities from neutron capture in Y/sup 89/ was prepared. The gamma spectrum from U/sup 238/ (n, gamma )U/sup 239/ was investigated between 0.14 and 7.6 Mev. Observed emissions are reported. Additional gamma energies observed in (n, gamma ) reactions with Ti/sup 49/ are listed; intensities are given relative to the 1.375 Mev emission previously reported. Gamma-gamma correlation measurements made on the 6.41-0.34 and 0.34-1.38 Mev cascades following neutron capture in Ti confirm the (1/2-) assignment to the 1.72 Mev level in Ti/sup 49/. Turbulence in NRU heavy water, causing the control rods to swing about their vertical position, was found to produce an 8 Mw power fluctuation at 200 Mw levels. Shrouds were placed around the rods to protect them from the turbulence. Short notes are included on a number of radation detection instruments being developed far reactor instrumentation. (For preceding period see PR-P-36.) (D.E.B.)

• Research Organization: Atomic Energy of Canada Ltd. Chalk River Project, Chalk River, Ont.
• NSA Number: NSA-12-010908
• OSTI ID: 4333524
• Report Number(s): PR-P-37; AECL-587
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-58
• Country of Publication: Canada
• Language: English

Related Subjects

PHYSICS
ABSORPTION- CADMIUM- CADMIUM RATIO- DISTRIBUTION- MEASURED VALUES- NEUTRON FLUX- NEUTRONS- NRU- REACTORS- SPECTRA- THERMAL NEUTRONS
ALPHA BEAMS- BERYLLIUM 7- DECAY- GAMMA RADIATION- - HELIUM 3- NUMERICALS- SUN- THERMONUCLEAR REACTIONS
ALPHA BEAMS- CARBON 14- ENERGY LEVELS- GAMMA RADIATION- NUCLEAR REACTIONS- OXYGEN 18
ALPHA PARTICLES- ANGULAR DISTRIBUTION- CAPTURE- GAMMA RADIATION- MEASURED VALUES- NITROGEN 14- NUMERICALS- RESONANCE
ALPHA PARTICLES- BEAMS- CROSS SECTIONS- EXCITATION- HELIUM 3- MEASURED VALUES- NUCLEAR REACTIONS- OXYGEN 15- OXYGEN 16- RESONANCE
ANGULAR DISTRIBUTION- CALIFORNIUM 252-