ALPHA PARTICLES AND PROTONS EMITTED IN THE BOMBARDMENT OF Au$sup 197$ AND Bi$sup 209$ BY C$sup 12$, N$sup 14$, AND O$sup 16$ PROJECTILES

Journal Article · Wed Nov 01 04:00:00 EST 1961 · Physical Review (U.S.) Superseded in part by Phys.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.124.877· OSTI ID:4830841

Britt, H C; Quinton, A R

Angular distributions, energy spectra, and absolute cross sections are measured for alpha particles emitted in the bombardment og Au/sup 197/ and Bi/ sup 209/ by Cn/sup 2/ N/sup 14/, and o/sup 16/ projecttiles at bombarding energies of 10.5 Mev/nucleon, and for the C + Bi reaction at energies of 8.7 and 7.l Mev/nucleon. Angular distributions and absolute cross sections are also measured for protons from the C + Bi and O + Bi reactions at energies of I0.5 Mev/ nucleon. It is found that, from the angular distributions and energy spectra, it is possible to separate the contributions froin direct and evaporation processes. The direct alpha particle results suggest that the principal direct process involved is the breakup of the incident projectile in an interaction with the surface of the target nucleus. At I0.5 Mev/nucleon energies, the cross sections for the emission of direct protons and direct alpha particles are found to be about 10% and 25 to 35%, respectively, of the calculated total reaction cross sections. The evaporation cross sections depend strongly on the excitation energy available in the compound system. The evaporation energy spectra can be fitted by an expression of the form exp(-E alpha /T) and the results yield anm average level density parameter, alpha = 22 plus or minus 2 Mev-1, for these reactions. (auth)

• Research Organization: Yale Univ., New Haven
• NSA Number: NSA-16-003744
• OSTI ID: 4830841
• Journal Information: Physical Review (U.S.) Superseded in part by Phys.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 D, Journal Name: Physical Review (U.S.) Superseded in part by Phys.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: 124; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALPHA PARTICLES
ANGULAR DISTRIBUTION
BISMUTH 209
CARBON 12
COMPOUND NUCLEI
CROSS SECTIONS
DIRECT REACTIONS
EMISSION
ENERGY
ENERGY LEVELS
ENERGY RANGE
EVAPORATION MODEL
EXCITATION
GOLD 197
INTERACTIONS
MEASURED VALUES
NITROGEN 14
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
NUMERICALS
OXYGEN 16
PHYSICS
PROTONS
SPECTRA
TARGETS