AN EXPERIMENTAL STUDY OF THE REACTION Al$sup 27$(d,n)Si$sup 28$ (thesis)

Technical Report · Tue Jan 01 00:00:00 EST 1957

OSTI ID:4244368

Rubin, A G

The neutron spectrum and angular distributions of neutron groups from Al/ sup 27/(d,n)Si/sup 28/ were obtained by the method of proton recoils in nuclear emulsions. A thin aluminum target was bombarded with 2.16 Mev deuterons, and neutrons were detected by means of 400 ic Ilford C-2 emulsions placed at nine angles to the incident beam. The plates were scanned with a Deitz binocular microscope equipped with a moving stages at 1000 magnification. Neutron spectra were obtained at eight angles; 0, 10, 20, 30, 45, 60, 90, and 120 . A total of 12,000 tracks was scanned. STA Excited states of Si/sup 28/ were obtained at 1.78 sintering time 0.10, 4.54 sintering time 0.2, 4.95 sintering time 0.2, 6.24 sintering time 0.06, 6.88 sintering time 0.06, 7.39 sintering time 0.06, 7.89 sintering time 0.06, 8.31 sintering00.06 Mev. The cross-section for formation of the 9.37 state at 0 sintering time is 10.1 mb per steradian, within a factor of two.! A second bombardment for the same reaction was made with a bombarding energy of 6.00 Mev in order to obtain valid stripping angular distributions. 400 ic Ilford C-2 emulsions were used at nine angles to the incident beams at 15 intervals from 0 to 135 . Neutron spectra were obtained at six of these angles. The angular distributions obtained were compared with tbe Butler stripping theory in order to obtain the parities and limits on the spins of the states in Si which were reached in the reaction. The angular distributions of neutron groups corresponding to the levels at 1.78, 6.24, by l = 0 distributions. STAThe angular distribution of the unresolved states at 4.6 and 5.0 Mev was obtained, and the principal peak matches a Butler l = 1 distribution. The states at 6.88 and 7.39 Mev were poorly resolved, and did not fit Butler distributions very well. An l = 2 distribution was obtained for the ground state of Si/sup 28/ as expected.! The cross-section for formation of the 9.39 Mev state of Si/sup 28/ at 0 at 2.16 Mev bombarding energy is 10.1 sintering time 5 mb per steradian, and at 6.00 Mev bombarding energy 30.6 sintering time 8 mb per steradian. The angular distributions obtained from this exposure followed the Butler predictions quite closely, out to the largest angles studied. A thorough analysis of the low bombarding energy angular distributions was not carried out. A thin target of isotopic boron was bombarded with 7.03 Mev protons. Tbe neutrons from the B/sup 11/(p,n)C/sup 11/ reaction, studied by means of nuclear emulsions, indicate an excited state of C/sup 11/ at 2.01 sintering time 0.06 Mev. The reaction P/sup 31/(p,n)S/sup 31/ was studieid at E/sup p/ = 17.2 Mev. The energy spectrum of the neutrons was determined by means of proton recoil measurements in nuclear emulsions. The mass excess, M - A, of S/sup 3/ was calculated to be-10.04 sintering time P 0.20 Mev. STAExcited states of S/ sup 31/ were located at 1.15 sintering time O.l5, 2.28 sintering time 0.20, 3.35 sintering time 0.20, 4.51 sintering time

• Research Organization: Boston Univ.
• DOE Contract Number: AF18(600)-997
• NSA Number: NSA-13-014783
• OSTI ID: 4244368
• Report Number(s): AFOSR-TN-57-636; AD-136623
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-59
• Country of Publication: United States
• Language: English

Related Subjects

PHYSICS AND MATHEMATICS
ALUMINUM 27- ANGULAR DISTRIBUTION- CROSS SECTIONS- DEUTERON BEAMS- ENERGY- ENERGY LEVELS- ENERGY RANGE- EXCITATION- ILFORD EMULSIONS- MEASURED VALUES- MICROSCOPY- NEUTRONS- NUCLEAR EMULSIONS- NUCLEAR REACTIONS- PARITY- PARTICLE TRACKS- PROTONS- RECOILS- RESOLUTION- SILICON 28- SPECTRA- SPIN
ANGULAR DISTRIBUTION- BORON 11- CARBON 11- ENERGY- ENERGY LEVELS- ENERGY RANGE- EXCITATION- ILFORD EMULSIONS- MEASURED VALUES- MICROSCOPY- NEUTRONS- NUCLEAR EMULSIONS- NUCLEAR REACTIONS- PARTICLE TRACKS- PROTON BEAMS- PROTONS- RECOILS- RESOLUTION- SPECTRA
ANGULAR DISTRIBUTION- ENERGY- ENERGY LEVELS- ENERGY RANGE-