Neutronics Analysis of the Divertor Interferometer Diagnostics inside the Lower Port #8 Plug of ITER with ATTILA 3-D CAD-Based FEM Code

Abstract

The Divertor Interferometer Diagnostics is located inside the 8th lower port plug of ITER and consists of 16 laser beam channels. The beam channels start from windows at the rear vacuum enclosure door of the port and pass through a shield block mounted on a structural sled. The cassette box of the laser beams is mounted on the central divertor cassette and the branching beams pass through the 20-mm gaps between the divertor cassette. Nuclear heating and damage (DPA and helium production) rats are calculated in structure of the divertor components and at the sensitive mirrors that direct the laser beams. Personnel dose rates are also calculated inside the port and at the inter space behind the port enclosure. The Distributed Memory Parallel (DMP) version of ATTILA code, SEVERIAN, is used in assessing the heating and damage rate while the dose rate analysis is performed using the serial ATTILA. A 40-degrees CAD model was constructed based on ALITE03 and ALITE04 MCNP CATIA model. About 1.88M cells were used with Sn32P3 approximation along with a 46n-21γ cross section library based on FENDL2.1.