MSCT and HEAT: Computer codes for simulation of multiscattering and thermal dissipation of charged particle beams in multiple thin metallic targets

Abstract

In order to produce the 195m' 9Hg/195mA~ genera tor for myocardial. studies (1,2 and references therein,3), the possibility to use on-line thermal diffusion/evaporation method was speculated (1,4). In fact, the Au/Hg separation is possible by thermal diffusion o f radio-Hg through thin Au sheets (either in vacuum or with an inert gas as a carrier) in the temperature range from 700 to 800 OC, b elow the gold melting point (1,4). A gold multitarget (GMT) made by 15 gold sheets, 50 pm thick (i.e: 0.75 mm Au = 3 3 . 3 -> 20 MeV proton energy loss ( 5 ) ) , distance<] from 3 to 7 mm one to the other, seems t o be suitable for on-lin(, separation of radio-H9 from gold using the proton beam power i tself (13.3 W/pA) for heating the system.In order to make a theoretical evaluation of the temperature profile Ti(x,y) induced by the proton beam on the i-th target, a computer code named HEAT was developed: ration: 1. -radial heat conduction diation (Stefan-Boltzmann law) and 3 cooling fluids (Newton law), as a profile Ji(x,y) on the i-th metallic Obviously the i-th temperature prof this code takes into conside-. 1-st Fourier law), 2. -irra--convection with carrier o r function of the incident beam sheet. le depends strongly on the J i (x,y) beam profile, whose shape depends strongly on the interaction with the previous (i-1)-th metallic sheet, as well as on the shape of the primary incident beam, J1(x,y), and the distances between and the thicknesses of the various sheets.S o , in order to evaluate the effect of multiscattering and plurime scattering ( 6 , 7 ) on the 15 gold sheets of the GMT, a Monte Carlo computer code named was developed (4). The code !ST can use the code HEAT as a subroutine.Any shape of the incident beam profile J1(x,y) can be used (gaus-

Computer simulation tools as applied to radioisotope production target design

“…11 It is designed more specifically for isotope targets based on a stacked foil geometry. Multiple Coulomb scattering is modeled in the MSCT module.…”