EXCITATION FUNCTIONS FOR THE ($alpha$$,$$alpha$n) AND ($alpha$,2pn) REACTIONS ON Ce$sup 14$$sup 2$

Journal Article · Mon May 15 04:00:00 EDT 1961 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

OSTI ID:4012293

Foreman, Jr, B M

Cross sections are measured radiochemically for the reactions Ce/sup 1// sup 4//sup 2/( alpha , alpha n)Ce/sup 1//sup 4//sup 2/ and Ce/sup 1//sup 4//sup 3/ at a heliumion energy of 16.8 to 40.1 Mev. The cross section for the ( alpha , alpha n) reaction begins to rise sharply at about 25 Mev and reaches a value of 69 plus or minus 5 mb at 40.1 Mev. The cross section for the ( alpha ,2pn) reaction begins to rise at about 32 Mev and reaches a value of 2.5 plus or minus 0.4 mb at 40.1 Mev. An upper limit of approximately 0.1 mb for the cross section for the reaction Ce/sup 1//sup 4//sup 2/( alpha , alpha p)La/sup 1//sup 4/ /sup 1/ in the energy range covered is also obtained. The results for the ( alpha , alpha n) and ( alpha , alpha p) reactions are discussed in terms of several mechanisms: compound nucleus formation and decay, knock-on, and direct inelastic scattering followed by neutron evaporation. The results seem to be most consistent with the last mechanism. The existence of a measurable cross section for the ( alpha ,2pn) reaction in this energy region suggests that the reaction proceeds mainly by He/sup 3/ emission, probably by a stripping mechanism. The data reported are consistent with the hypothesis that in this energy range at most one particle is emitted as a result of direct interaction. (auth)

• Research Organization: Brookhaven National Lab., Upton, N.Y.
• NSA Number: NSA-15-018802
• OSTI ID: 4012293
• Report Number(s): BNL-5152; 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• Journal Information: Physical Review (U.S.) Superseded in part by Phys.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 D, Journal Name: Physical Review (U.S.) Superseded in part by Phys.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: 122; ISSN PHRVA
• Country of Publication: United States
• Language: English

Related Subjects

ALPHA PARTICLES
CERIUM 141
CERIUM 142
CERIUM 143
COMPOUND NUCLEI
CROSS SECTIONS
DECAY
DIRECT REACTIONS
EMISSION
ENERGY RANGE
EVAPORATION
EXCITATION
HELIUM 3
INELASTIC SCATTERING
LANTHANUM 141
MEASURED VALUES
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
PHYSICS
PROTONS
RADIOCHEMISTRY
SCATTERING
STRIPPING