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Monoenergetic electrons of energies from 3.2 to 14 MeV provided by a linear accelerator have impinged normally on thick solid targets. Backscattered electrons have been detected by an ionization chamber, the multiplication factor of which was calibrated with a Faraday chamber as a function of average energy per backscattered electron. Angular distributions of backscattered electrons measured for a total of seven targets, effectively semi-infinite and ranging in atomic numbers from 4 to 92, show a trend similar to Dressel's result. However, the backscattering coefficients obtained are lower than his values and are consistent with those reported by other previous authors. Variations of angular distribution and backscattering coefficient with target thickness also have been investigated for Cu, Ag, and Au targets at an incident energy of 6.1 MeV. Some of the angular distributions observed were compared with results of a simple calculation proposed by the author, and an interpretation has been given that the relative contribution of sidescattering compared with that of diffusion increases with increasing energy in the region considered. Backscattering coefficients for the thinnest targets of lower atomic numbers level o toward a nonzero intercept similar to Cohen and Koral's lower-energy result. This tendency is considered to be caused by the contribution of energetic secondary electrons. The backscattering coefficient 𝜂(E0, Z, ∞) of electrons incident on the semi-infinite target of atomic number Z with kinetic energy E0 above 1 MeV is expressed by an empirical equation 𝜂(E0, Z, ∞) = 1.28 exp[11.9Z-0.65(1 + 0.103Z0:37E00:65)] (E0 in MeV), appreciable deviations from experimental data occurring only for Z≤6 and Z/E0≲2 MeV-􀀀1.

application/pdf, Bulletin of Osaka Prefecture University. Series. A, Engineering and natural sciences. 1998, 46(2), p.71-78

application/pdf, Bulletin of Osaka Prefecture University. Series. A, Engineering and natural sciences. 1997, 45(2), p.99-103

application/pdf, Bulletin of University of Osaka Prefecture. Series A, Engineering and natural sciences. 1995, 44(1), p.41-46

Charge-deposition distributions in absorbers irradiated by electrons have been computed by using the ITS Monte Carlo system version 3.0. Plane-parallel electron beams with energies from 0.1 to 100 MeV have been assumed to impinge normally on absorbers of effectively semi-infinite thickness. Absorber materials considered are elemental solids with atomic numbers between 4 and 92. Trends displayed by the results are discussed. The results at 10 MeV are compared with experimental data at 11.5 MeV published earlier, showing good agreement. The comparison also reveals that an appreciable discrepancy reported for Be between the experimental data and the result computed with an old version of the ETRAN Monte Carlo code has been resolved by the recent improvement of the energy-loss straggling algorithm used both in ETRAN and ITS.

application/pdf, Bulletin of University of Osaka Prefecture. Series A, Engineering and natural sciences. 1994, 43(1), p.77-82

The component of energy deposition due to radiative processes (bremsstrahlung component) in absorbers irradiated by electron beams has been computed together with the total energy deposition by using the ITS Monte Carlo system version 3.0. Plane-parallel electron beams with energies from 0.1 to 100 MeV have been assumed to be incident normally on the slab absorber, whose thickness is 2.5 times the continuous slowing-down approximation (csda) range of the incident electrons. Absorber materials considered are elemental solids with atomic numbers between 4 and 92 (Be, C, Al, Cu, Ag, Au and U). An analytic formula is given to express the depth profile of the bremsstrahlung component as a function of scaled depth (depth in units of the csda range), incident-electron energy and absorber atomic number. It is also applicable to compounds.

application/pdf, Bulletin of University of Osaka Prefecture. Series A, Engineering and natural sciences. 1994, 42(2), p.193-207

application/pdf, Bulletin of University of Osaka Prefecture. Series A, Engineering and natural sciences. 1993, 41(2), p.69-76

application/pdf, Bulletin of University of Osaka Prefecture. Series A, Engineering and natural sciences. 1993, 41(2), p.103-118

application/pdf, Bulletin of University of Osaka Prefecture. Series A, Engineering and natural sciences. 1991, 39(2), p.241-244