Yields and recoil properties of products from the reaction between natural copper and 86 MeV/A12C ions

Abstract

Absolute cross sections and thick target/thick catcher recoil properties have been determined for radionuclides produced in the reaction between copper and 86 MeV/A ~2C ions. Integration of the obtained mass yield curve gives a cross section of reactions leading to spallation products of 1,440 mb.The F/B-ratios are found to increase with decreasing product mass, reaching a maximum of ~ 100 for products with masses 20-25 mass units lower than the target mass, followed by a decrease. The recoil data have been analyzed with the two-step vector model to deduce momentum transfer and product kinetic energies. The momentum transferred to an intermediate system is found to increase for reactions leading to decreasing product masses, reaching values of 1/3 of full momentum transfer. The derived mean kinetic energies are found to be higher than found in comparable proton induced reactions. Some possible explanations for this phenomenon have been discussed. The results have been compared with Monte Carlo cascade-evaporation calculations, and the agreement between the predictions and experiment is in general found to be good.

Heavy fragment energies and angular distributions in the reaction of 86 MeV/nucleon12C with medium-A targets

“…In such a way, as examples at= 1.7 barns for a 89y target and O-r=2.1 barns for a natural silver target with an error of 15 to 20 ~o. The thick target between thick catchers technique has not been used for the natural Cu target; nevertheless, summing partial cross-sections in thin catchers and in target, an estimation of the total cross-section has been made in order to compare the results with the measurement performed by Lund and coworkers [1][2][3][4][5][6][7][8][9][10][11][12][13]. The two different experiments appear in quite good agreement, as indicated in Table 1.…”

Spallation of V induced by 1 GeV12C-ions and by 258, 350 and 910 MeV3He-ions

“…This is consistent with the findings of Cumming et al [17J, who bombarded Cu target with different projectiles and showed that the velocity vll(/~ll ) plotted versus the projectile velocity (rapidity) for a given isotope fall on a common smooth curve. However, by extracting v ll from the VcN same data, this appears to be a smooth function of 0,4 the projectile total kinetic energy, as we pointed out 0,3 in an earlier paper [11]. The vii for products far from the target is signi-0,2 ficantly lower for 86 MeV/A aHe induced reactions than for the corresponding 86 MeV/A ~2C reactions.…”

“…It became possible to study nuclear interactions with heavy ions at intermediate velocities and thus to learn about the transitions between slow (< 10 MeV/A) and relativistic heavy ions. Some of the results obtained have been published [1][2][3][4][5][6][7][8][9][10][11][12][13]. A more or less complete * Present address: CERN, Geneva, Switzerland picture of the systematic dependence on the projectile type, projectile energy, target and product mass is taking form.…”

“…Cumming et al [17] have recently shown that the R -vii longitudinal momentum vlt or ell-c-imparted to the cascade residuals in reactions induced by different projectiles over a wide energy (or velocity) range, depends only on the projectile velocity (or rapidity=tanh-1/3) and is independent of projectile mass. However, deducing the fractional momentum transfer, Vrr/VCN from the same data it can be shown to be a smooth function of the projectile total kinetic energy [11]. The experiments executed on the SC-machine today have been focused on the 86MeV/A I2C induced reactions.…”

“…The purpose of the present work was to obtain information on the general pattern of the spallation of a relatively light nucleus like si V by aHe-ions at different energies and to compare these patterns when the incident particles were *2C-ions. This is a part of a more extended examination of the systematic variation of cross section and thick target-/thick catcher recoil properties for products formed in 3He and 12C [- [10][11][12] induced reactions in light, medium and heavy mass targets. Monte-Carlo cascade-evaporation codes have recently been developed for heavy ions induced reactions [18][19][20].…”