A method has been developed to purify bulk amounts of natural thorium from its daughter products. The method is based on anion exchange separation of Th from Pb, Bi, Tl, Ra using Dowex 1 X 8 anion exchange resin conditioned to 2M HCl. The method has several advantages over other methods, namely the decontamination is quite high, Th separation is quantitative and it is suitable for the purification of bulk amounts of Th in a reasonably short time.
Isomer ratios for87Y,86Y and84Rb from -induced reactions on85Rb in the energy range between 20 and 60 MeV have been measured. The data show a characteristic increase followed by a decrease with the increase in bombarding energy. The fall in the isomer ratio values are explained on the basis of enhanced angular momentum depletion by the precompound particles and thereby leaving the compound system at low angular momentum states. A different reaction mechanism has been proposed for the low yield of the high spin isomer in the /, n/ reaction in85Rb.
Authors:V. Bhargava, V. Rao, S. Marathe, S. Sahakundu, and R. Iyer
A radiochemical method is described for the separation of heavier rare earths from the fission of uranium. The method is particularly
suitable for the separation of low yield (10−5%–10−7%), highly asymmetric rare earth fission products viz.179,177Lu,175Yb,173Tm,172,171Er,167Ho and161,160Tb in the neutron induced fission of natural and depleted uranium targets. Additional separation steps have been incorporated
for decontamination from239Np (an activation product) and93-90Y (a high fission-yield product) which show similar chemical behaviour to rare earths. Separation of individual rare earths
is achieved by a cation exchange method performed at 80°C by elution with α-hydroxyisobutyric acid (α-HIBA).
Authors:S. Sahakundu, S. Marathe, V. Rao, V. Bhargava, and R. Iyer
A new method for obtaining radiochemically pure67Cu from highly active fission product solutions is described. The method is based on the solvent extraction of the Cu(II)-diethyldithiocarbamate
complex in n-butyl acetate in the presence of hold-back carriers for Ni, Co, Mn, Mo, rare earths, Cd, Te and Sb, and subsequent
purification steps involving scavengings for Ag, Ba, Sr and Fe followed by an anion-exchange purification step for decontamination
from Te. Copper is finally extracted as the α-benzoin oxime complex in which form it is mounted and counted. The method has
several advantages over other methods in that decontamination is very high and it is sufficiently fast considering the stringent
radiochemical purity achieved. The67Cu separated by this procedure from a one-day-old mixture of fission products arising from 1010 fissions was found to be completely free of any contamination.
Authors:R. Guin, S. Saha, S. Sahakundu, and Satya Prakash
The decay of 33 min 2+ isomeric state of104Ag has been studied.104Ag has been produced following the103Rh(, 3n) and107Ag(, 3n) reactions using 29 and 55 MeV -particles, respectively. The present results indicate that104mAg decays mainly by EC/
+ decay. The IT branch for this decay was found to be <0.07% as against the reported value of 33±5%.
Authors:A. Ramaswami, B. Srivastava, S. Sahakundu, S. Manohar, Satya Prakash, and M. Ramaniah
The fractional cumulative yields of135I,138Xe and140Ba in the particle (30 MeV) induced fission of232Th have been determined following the growth and decay of135gXe,138gCs and140La, respectively, employing high resolution gamma ray spectroscopy. The fractional cumulative yield values are 0.766±0.02, 0.813±0.03 and 0.991±0.004, respectively. The analysis of the data indicates a broader width of charge distribution () compared to the normally observed =0.56±0.06 for thermal neutron fission of235U.