RARE NUCLEAR REACTIONS INDUCED BY 14.7-Mev NEUTRONS

Journal Article · Sun Sep 15 00:00:00 EDT 1963 · Physical Review (U.S.) Superseded in part by Phys.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.131.2649· OSTI ID:4648878

Bramlitt, E T; Fink, R W

Activation cross sections for 14.7 plus or minus 0.2-Mev neutrons were measured for STA(n,n alpha ) + (n, alpha n)! reactions with Cu/sup 65/ Zn/sup 70/ , Ga/sup 71/, and Nb/sup 93/, while upper limits were set for this reaction for V/ sup 51/, Ge/sup 76/, Br/sup 81/, Rb/sup 87/, Ag/sup 107/, Ag/su p 109/, In/sup 115/, Au/sup 197/, and Tl/sup 203/. Cross-section limits also were set for (n,2p) reactions on Si/sup 29/, K/sup 41/, Sc/sup 45/, Ti/sup 50/, V/sup 51/, Mn/ sup 55/, As/sup 75/, Y/sup 89/, Nb/sup 93/, Cs/sup 133/, La/sup 139/, Pr/sup 141/ , and Tb/sup 159/; and for (n,He/sup 3/) reactions on Sc/sup 45/, Nb/sup 93/, Au/ sup 197/, and Tl/sup 205/. Cross sections were dete rmined for (n, gamma ) reactions on Y/sup 89/, Nb/sup 93/, and Pr/sup 141, and upper limi ts were set for (n,3n) reactions with Pr/sup 141/, Au/sup 197/, and Tl/sup 203. The ISTAn,np) + (n,np)! reaction was detected with Ni/sup 58/, but not with Mo/sup 92/ . A value of 520 plus or minus 120 mb was established for the former, and an upper limit set for the latter. Absolute disintegration rates were obtained by both beta and gamma spectroscopy counting methods. Extensive use of radiochemical separation was made in order to isolate the low-yield rare reaction products from large target samples. Statistical theory was employed (using parameters selected from a critical analysis of the literature) to make theoretical cross section estimates for many of the reactions studied. The theoretical cross sections for (n, alpha n) reactions agree remarkably well with the experimentally determined STA(n,n alpha ) + (n, alpha n)! cross section sums, thereby suggesting that the path for this reaction may be predominantly the (n, alpha n) process. For certain cases, statistical theory predicts appreciable (n,2p) cross sections at 14.7 Mev; e.g., for Cr/sup 50/, Ni/sup 55/, Kr/sup 78/, and Mo/sup It is suggested that in studies of emitted proton spectra which show an excess of low-energy protons, a contribution may be present from the (n,2p) as well as the (n,np) reaction. A new gamma at 176 plus or minus 4 kev in about 5% of 1.8-day Sc/sup 48/ decays is confirmed. (auth)

• Research Organization: Univ. of Arkansas, Fayetteville
• NSA Number: NSA-17-036707
• OSTI ID: 4648878
• Report Number(s): TID-19037; 0031-899X
• 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: 131; Other Information: TID-19037. Orig. Receipt Date: 31-DEC-63
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

PHYSICS
ACTIVATION
ALPHA PARTICLES
ARSENIC 75
BROMINE 81
CESIUM 133
CHROMIUM 50
COPPER 65
COUNTERS
CROSS SECTIONS
DECAY
EMISSION
ENERGY
GALLIUM 71
GAMMA RADIATION
GERMANIUM 76
GOLD 197
HALF-LIFE
HELIUM 3
INDIUM 115
KRYPTON 78
LANTHANUM 139
MANGANESE 55
MEASURED VALUES
MEV RANGE
MOLYBDENUM 92
NEUTRON BEAMS
NICKEL 58
NIOBIUM 93
NUCLEAR REACTIONS
POTASSIUM 41
PRASEODYMIUM 141
PROTONS
RADIATION DETECTORS
RADIOCHEMISTRY
RUBIDIUM 87
SCANDIUM 45
SCANDIUM 48
SILICON 29
SILVER 107
SILVER 109
SPECTRA
SPECTROSCOPY
STATISTICS
TARGETS
TERBIUM 159
THALLIUM 203
THALLIUM 205
TITANIUM 50
VANADIUM 51
YTTRIUM 89
ZINC 70