Recoil Properties of Fission Products

Abstract

The range and relative rates of energy loss in Al and Au have been measured radiochemically for five products from thermal-neutron-induced fission of U235. Range-velocity relationships for the median light product of fission and the median heavy product have been obtained from these measurements and other workers' energy-loss data. The relation of range (R) to energy (E) or velocity (v) can be fitted to functions of the form .R = kV-or R We have assumed that these functional forms can be applie.d to fission products of any mass. The constants K and. were determined from values of the range and kinetic energy for products of high yield. The values of these .constants have been extrapolated to products of low yield. We have estimated kiretic energies, heretofore unmeasured, from the ranges of low-yield products. We have interpreted certain radiochemical observations in terms of the average component of the range perpendicular to the original velocity. The value of this component in Au has been estimated to be about one-fifth the total range. This report was prepared as an account of Government sponsored work. Neither the United States, nor the Commission, nor any person acting on behalf of the Commission: Makes any warranty or representation, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, appáratus, method, or process disclosed'in this report may not infringe privately owne.d rights; or Assumes any liabilities with respect to the use of, or for damages resulting from the use of any information, apparatus, method, or process disclosed in this report. As used in the above, "person acting on behalf of the Commission" includes any employee or contractor of the Commission, or employee, of such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, or provides access to, any information pursuant to his employment or contract with the Commission, or his employment with such contractor.

Development of the Ultra-microhardness Technique for Post Irradiation Examination of Fuel Cladding Tubes

“…The diffusion coefficient of fission products in UOZ fuel has been reported to be two or three orders of magnit,ude larger than that for out-of-reactor tests(ls). Considering experimental result and t,liat the stopping range of fission fragments of UOz, around 10pm (19), is deeper than the maximum depth of the hardness distribution, we can see in the case of oxygen in fuel cladding tubes that neither neutron irradiation nor bombardment of fission fragments affects the diffusion coefficient.…”

Recoil studies of fission products formed in the fission of 238U by protons of energies 25–85 MeV

“…Alexande r et al (27,36,48 ) measured the ranges and kinetic energies of several fission products produced from 0.72, Furtherm ore, the neutron-deficien t products were found to be formed from high-dep osition events and the neutron-rich products from low-depo sition events. The choice of shielded and cumulativ e isotopes helps to explain sorne of the mechanism s of the fission.…”

“…In order to evaluate c, ranges of fragments in thermal neutron fission of 235u , measured by various authors for several stopping materials (Al (30,31,36,37,38,39,40), Zr (43), Au (36) and U (31» were converted to peE) and the kinetic energies E by use of the equations of Lindhard et al (34). These values of peE) and E …”

Recoil studies of some light-mass products from the proton-induced fission of 238U at intermediate energies

“…It should be pointed out that for the mass region of our interest, no charge dependence of the range-energy relationship has been postulated in using eq. [2]. For personal use only.…”

“…Information about the momentum The study of recoil ranges of fission products has proved to be of considerable interest in providing useful information about the fission process. A number of investigations involving measurements of recoil ranges (1)(2)(3)(4)(5)(6)(7)(8) have been made by the use of a thick target -thick catcher technique. All these experiments involve the measurement of the average ranges of fission products and the subsequent conversion of the ranges into kinetic energies of these products by the use of a suitable range-energy relationship.…”