Distribution of Radionuclides from the Interaction of 3- and 29-GeV Protons with Silver

Abstract

reaction in the energy range considered (6.4-8.7 MeV) excites, altogether, 42 states, compared to a total of eight (d,p) transitions in the corresponding 49 Ti range (0-2.3 MeV).If the DW calculations are extrapolated from the bound to the unbound region, keeping the bound-state wave function fixed near zero binding, the estimated ( 3 He,d) strengths of the two 1=1 transitions to the analog states (levels 76 and 82) are «0.4 and -0.15, respectively. The corresponding AS Ti(d,p) strengths divided by (2T+1) = 5 are 0.5 and 0.12, respectively. ACKNOWLEDGMENTSThe authors wish to thank Professor R. Middleton and Professor W. E. Stephens for their continued interest in this work. It is a pleasure to acknowledge the help of Dr. R. H. Bassel in performing part of the distorted-wave analysis, and also P. Neogy, who assisted with the data analysis. The excellent service rendered by the NEUCC computing centre in Lundtofte, Denmark is greatly appreciated. The scanning of the nuclear emulsions was carefully performed by Mrs. M. Scrinivasan and Mrs. C. Coliukus. emulsions, bubble chambers, mass spectrometry, and radiochemistry. The last two methods have been used to measure product cross sections from the reaction of GeV protons with various targets. 3-7 However, no complete 3 Formation cross sections have been measured of about 60 radionuclides isolated from Ag irradiated by 3and 29-GeV protons. From these data, isobaric charge distributions and mass-yield curves were derived. At 3 GeV, the total isobaric cross sections are ^40 mb near the target, and they decrease to a broad minimum of 4 mb at around A = 30-40. For lighter products the cross sections increase again. At 29 GeV, light-and intermediate-mass products (20 <A <50) have 20-100% higher cross sections than at 3 GeV; the heavier products (A >65) have 10-20% lower yields. Corresponding charge-distribution curves at the two energies are identical except for shifts in absolute magnitude. Comparison of the 3-GeV mass-yield curve with the results of a Monte Carlo calculation based on a cascade-evaporation model shows that such a mechanism can account for the observed cross sections down to about mass 50. The lower-mass products (15<^4<35) must be formed mainly in a fragmentation or "fission-like" process. Comparisons are made with previous nuclear-emulsion and radiochemical results.

DEEXCITATION PROCESSES IN NUCLEAR REACTIONS. Progress Report, May 1971-- April 1972.

“…The analysis of the data for the remaining nuclides as well as for shorter-and-longer-lived products produced in separate irradiations is currently in progress. Also listed in the table are similar results obtained by Katcoff et al (10) in conventional radiochemical experiments. The present cross sections tend to * be smaller but it is possible that a more refined analysis, still to be performed, will lead to inproved agreement.…”

Spallation Yields from Natural Rb, Sr and Y Irradiated with 100 MeV and 200 MeV Bremsstrahlungs

“…Some results on high energy proton-induced spallations [7,8] are included. In the table, the width of the charge dispersion is expressed by FWHM of A(N/Z) and by the corresponding Z-spread, ΔΖ.…”

Nuclear reactions of silver with 25.2 GeVC12ions and 300 GeV protons

“…The open points refer to proton bombardments and the closed points to~2 C. The curves are based on Eqs. (1) and(2). The dashed extensions above A =100 are based on a separate analysis of the data in this mass region.…”