C. B. Chitwood

Limitations on linear momentum transfer in 14N induced reactions on 238U at EA=15, 20, 25 and 30MeV☆

Abstract Linear momentum transfer distributions have been dermimined for 14 N induced reactions on 238 U by measuring the folding angle between two coincident fission fragments. The data follow the systematic trends previously established for alpha conjugate projectile nuclei. Over the range of energies investigated, the most probable linear momentum transfer has not reached a limiting value. Extrapolation of the present results indicates that complete fusion should cease to be a relevant reaction mechanism above incident energies of E A =40−45 MeV

Emission of complex nuclei in 12C induced reactions at EA = 15 and 30 MeV☆

Abstract Cross sections for emission of complex nuclei (Z ≈ 3–20) with energies close to the exit channel Coulomb barrier increase by more than one order of magnitude for 12C induced reactions on Au between the incident energies of E A = 15 and 30 MeV. For reactions on Ag at E A = 30 MeV , the element yields exhibit a characteristic power law dependence. Simple statistical calculations reproduce the qualitative trends of the element yields.

Azimuthal correlations between light particles emitted in 12O induced reactions on 12C and 197Au at 400 MeV

Abstract Azimuthal correlations between light particles emitted to polar angles of 40 and 70 degrees with respect to the beam axis were measured for 16 O induced reactions on 12 C and 197 Au at 400 MeV. Coincident light particles are preferentially emitted in a plane which contains the beam axis. For reactions on 12 C, coincident light particles are preferentially emitted to opposite sides of the beam axis. These correlations may be understood in terms of the phase constraints imposed by momentum conservation on systems with finite number of nucleons. For reactions on 197 Au, on the other hand, preferential emission of coincident deuterons and tritons to the same of the beam axis may be caused by the shadowing of preequilibrium particles by the adjacent cold spectator nuclear matter.

Light particle emission in fusion-like 14N + 197Au collisions at E/A = 35 MeV☆

Abstract Single- and two-particle inclusive cross sections for light nuclei (p, d, t, 3,4 He, 6–9 Li, 7,8,10 Be) were measured for 14 N induced reactions on 197 Au at E / A = 35 MeV. At forward angles, θ ≈ 20°, quasi-elastic peripheral reactions and more violent fusion-like collisions were discriminated by measuring the folding angle between two coincident fission fragments resulting from the decay of the heavy reaction residue. More pronounced correlation functions, but very similar emission temperatures are observed for fusion-like collisions as compared to peripheral collisions.

Two-particle correlation functions at small relative momenta for 14N induced reactions on 197Au at E/A = 35 MeV

Abstract Two-particle correlation functions at small relative momenta were measured for light particles (p, d, t, α) emitted in 14 N induced reactions on 197 Au at E / A = 35 MeV. Energy dependent emission source radii are extracted with final-state interaction techniques.

Energy dependence of source radii and emission temperatures for 14N induced reactions at EA = 35 MeV

Abstract Correlations between coincident alpha particles and deuterons emitted in 14 N induced reactions on 197 Au at E A = 35 MeV are measured. Source radii ( r 0 ≈ 3−4 fm) and emission temperatures ( T ≈ 9−3 MeV) are extracted and shown to depend on the kinetic energy of the emitted particles.

Dependence of two-particle correlation functions on linear momentum transfer to a composite system

Abstract Light particle correlations at small relative momenta were measured in coincidence with two fission fragments for 14N induced reactions on 197Au at E/A = 35 MeV. The selection of large linear momentum transfers to the heavy reaction residue leads to a strong suppression of the beam velocity component of the light particle spectra and to enhanced maxima in the p-p and α-d correlation functions.

External Coulomb distortion of proton-deuteron final-state interactions for induced reactions on Au at E/A = 35 MeV

Abstract Correlations between coincident protons and deuterons were measured for induced reactions on Au at E / A = 35 MeV. Because of their different mass-to-charge ratios, protons and deuterons experience different accelerations in the Coulomb field of the heavy target residue. Correlations measured at small relative momenta are, therefore, influenced not only by the interaction between the coincident particles but also by this external field. The modification of the p−d correlation function by this field suggests that emission occurs close to the surface of the target residue.

Energy dependence of source radii and emission temperatures for induced reactions at

Abstract Correlations between coincident alpha particles and deuterons emitted in 14 N induced reactions on 197 Au at E A = 35 MeV are measured. Source radii ( r 0 ≈ 3−4 fm) and emission temperatures ( T ≈ 9−3 MeV) are extracted and shown to depend on the kinetic energy of the emitted particles.

Energy dependence of source radii and emission temperatures for 14N induced reactions at E A = 35 MeV

Abstract Correlations between coincident alpha particles and deuterons emitted in 14 N induced reactions on 197 Au at E A = 35 MeV are measured. Source radii ( r 0 ≈ 3−4 fm) and emission temperatures ( T ≈ 9−3 MeV) are extracted and shown to depend on the kinetic energy of the emitted particles.