Target mass dependence of neutron emission in collisions with 35 MeV/nucleon /sup 14/N ions

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.38.170· OSTI ID:7145147

Kiss, A; Deak, F; Seres, Z; Caskey, G; Galonsky, A; Heilbronn, L; Remington, B

Energy and angular distributions of neutrons emitted from collisions of 35 MeV/nucleon /sup 14/N ions with carbon, nickel, and holmium nuclei were measured. The neutrons were in coincidence with Li, Be, B, or C fragments at angles from 7/sup 0/ to 23/sup 0/ in the plane of the neutron detectors and at 15/sup 0/ out of this plane. Using fragment velocity bins of width corresponding to E/A = 7 MeV, we find the shapes of the neutron spectra above 15 MeV to be similar for the different targets for a given coincident fragment species, velocity bin, and angle. The cross sections are discussed in terms of moving thermal sources. In all cases the velocity and temperature parameters of the intermediate rapidity source are consistent with E/A = 8.5 +- 2.5 MeV and T = 9 +- 2.5 MeV, respectively. In agreement with a simple stripping-pickup model, the associated neutron multiplicities of this source decrease approximately linearly with the velocity of the coincident light fragments for fragment angles less than or equal to15/sup 0/. Using the model to compute the mass of the source, we find that, with some fluctuations, these multiplicities are proportional to the mass. Also, the linear relationship is approximately the same for the three targets. The temperature parameters of the target-like source are between 1 and 3.5 MeV for all three targets, while the associated neutron multiplicities increase considerably with target mass. For colinear neutron-fragment coincidences for a given projectile-like isotope, the neutron multiplicities associated with the projectile-like source are about the same for all three targets, indicating that the average excitations of the parent fragments are similar.

• Research Organization: Department of Atomic Physics, Eoetvoes University, H-1088 Budapest, Hungary
• OSTI ID: 7145147
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 38:1; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCELERATORS
ANGULAR DISTRIBUTION
CARBON
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
CROSS SECTIONS
CYCLIC ACCELERATORS
CYCLOTRONS
DATA
DISTRIBUTION
ELEMENTS
EMISSION
ENERGY RANGE
EXPERIMENTAL DATA
FRAGMENTATION
HEAVY ION REACTIONS
HOLMIUM 165 TARGET
INFORMATION
ISOCHRONOUS CYCLOTRONS
METALS
MEV RANGE
MEV RANGE 100-1000
MSU CYCLOTRONS
MULTIPLICITY
NEUTRON EMISSION
NEUTRON SPECTRA
NICKEL
NITROGEN 14 REACTIONS
NONMETALS
NUCLEAR REACTIONS
NUMERICAL DATA
SPECTRA
TARGETS
TIME-OF-FLIGHT METHOD
TRANSITION ELEMENTS