Nuclear radiation analysis of the IGNITEX experiment

Abstract

The fusion ignition experiment IGNITEX is designed to produce DT-ignited plasmas for scientific study inexpensively. The IGNITEX device will use a single-turn, toroidal field magnet and will rely solely on ohmic heating for obtaining ignition conditions. One-dimensional transport calculations using ANISN and the CLAW-IV cross-section library have been performed to determine the neutron and prompt photon fluxes throughout the IGNITEX device. The REAC2 activation and decay code has been used to calculate activation, decay heat, and photon source from radioactive decay. The time-dependent radioactive material inventories from REAC 2 were also used to specify the photon source for ANISN calculations to estimate the dose rate at various positions inside and outside the device as a function of operating history. The results of the radiation transport analyses indicate several desirable features for IGNITEX. All of the long-lived activation products will meet the criteria for disposal as low-level waste by orders of magnitude. Activation of air is lower than that predicted for other ignition experiments in which the plasma column is not shielded by the magnets. The location of the cryostat on the outside of the thick copper coil reduces liquid nitrogen activation and makes tritium production in the cryostat negligible. The area just outside of the magnet should be accessible for maintenance after two days of decay.<>