EVALUATION OF THE NEUTRON AND GAMMA-RAY HEATING IN THE RADIATION SHIELDING AND MAGNET COILS OF THE VISTA SPACECRAFT

Basic nuclear data for a design concept with inertial fusion energy pr opulsion for manned or heavy cargo deep space missions beyond earth or bit have been evaluated Fusion power deposited in the inertial confine d fuel pellet debris delivers the rocket propulsion with the help of a magnetic nozzle. The superconducting magnets of the magnetic nozzle a re protected against neutron and gamma-ray radiation by a massive shie lding, Throughout the shielding, the nuclear heating, caused by neutro ns and gamma rays has been calculated. As a critical issue Sor this de sign concept, special attention is paid to the nuclear heating in the superconducting magnet coils. The neutron and gamma-ray penetration in to the coils is calculated using the S-n,methods with a high angular r esolution in r-z geometry in S16P3 approximation by dividing the solid space angle in 160 sectors. Total peak nuclear heat generation densit y in the coils is calculated as 64.5 mu W/cm(3) by a fusion power of 1 7500 MW Peak neutron heating density is 30,8 mu W/cm(3) and peak gamma -ray heating density is 40.6 pW/cm(3) (on a different point). However; volume-averaged heat generation in the coils is much lower namely 2.1 7, 8.49, and 10.66 mu W/cm(3) for neutron, gamma-ray, and total nuclea r heating, respectively. A conically shaped frozen hydrogen expellant reduces the neutron streaming toward the spacecraft by a deflection in to vacuum, in addition to the geometric neutron flux attenuation in sp ace by 1/r(2). The results of these calculations can help to increase the credibility of the vehicle for interplanetary space transport appl ications design concept.