Photospallation of Complex Nuclei at Intermediate Energies. I

Abstract

Data are presented for photospallation yields from "^Au, '"La, '"Cs, '"I, ®'Y, "Co and "V targets measured at bremsstrahlung end-point energies (£0) from 30 to 1050 MeV in steps of 100 MeV or less with the aid of suitable radiochemical Separation. The measurements were performed for 40 nuclides from "^Au, 52 from '"La, 44 from '"Cs, 28 from '"I, 31 from ®'Y, 27 from "Co and 22 from "V. The observed yields were either independent or cumulative. For the latter, the precursor-corrected values are also presented. The present results are compared with the available literature data in a form of EQdependence. Isomer yield ratios for 38 pairs were also studied in terms of EQ-, target mass-and spin-dependence.

Photospallation of Complex Nuclei at Intermediate Energies. III: Comparison with PICA Calculation

“…It is noted that the isotopic distribution patterns for 51 V spallation in Fig. 1 a are narrow and symmetric, as observed and also as empirically reproduced by the Rudstam's formula [1,2], while the patterns for 133 Cs in Fig. lb are very broad and asymmetric, showing high yields at small χ for each of (y,0 -3pxn) reactions.…”

“…The nuclide yield data presented in the preceding paper I [1] were in units of milli-barn per equivalent quantum (mb/eq.q.) for 22 nuclides from 51 V, 27 from 59 Co, 31 from 89 Y, 28 from 127 1,44 from 133 Cs, 52 from 139 La and 40 from 197 Au at a high E 0 .…”

“…Our efforts have, therefore, been focused on obtaining theoretical and/or empirical predictions with good precision and accuracy for these purposes. The works reported in the preceding papers [1,2] are examples. One of the empirical formulae derived mostly from proton-induced spallations by Rudstam has been known to be applicable also to bremsstrahlung-induced ones over a wide range of combinations of targets and products, when the parameter values involved in the formula are suitably modified [5,6], While the involved parameters have been thought to have some physical implications for the process [7], a better and more detailed insight into the reaction mechanism is expected from a model incorporating reasoned physics.…”

“…In the preceding papers (parts I and II) [1,2], we presented the nuclide yield data on bremsstrahlunginduced spallation of 51 V, 59 Co, 89 Y, 127 I, 133 Cs, 139 La and 197 Au at end-point energies (E 0 ) up to 1000 MeV and their systematic features characterizing photospallation at these energies deduced with use of Rudstam's empirical formula [3]. Our previous results on the photospallation of nat Cu [4] were also included in the analysis.…”

Recoil properties of radionuclides formed in the photonuclear reactions onnatCu at intermediate energies

“…We have been measuring the yields of bremsstrahlung-induced photopion reactions, 1-4 photospallation, [5][6][7][8] photofragmentation, 9 and/or photofission 10 from 7Li to 2~ targets using radiochemical techniques in order to study the systematics of photonuclear reactions and to investigate reaction mechanisms and nuclear structure. Many fruitful informations about these aspects have been obtained so far, but all based on the yield measurements of reaction products.…”