BTR code recent modifications for multi-run operation

Abstract

BTR code (Beam Transmission with Re-ionization) has been used for many years in the design and performance optimization of Neutral Beam Injection (NBI) systems based on negative or positive ion sources. BTR beam formation and transmission along the beam line is simulated by a simple and comprehensive 6D beam model, which accounts for beam losses and power deposition on the injector surfaces. Beam particles are followed in a deterministic manner in electromagnetic fields, with transforming on gas and plasma targets, including the neutralization and ionization in gas or plasma. Power flux and power deposition profiles are the main BTR output which can be calculated in any plane along the injector. For older BTR versions, each single Run (or beam start) supposed a direct data input through user interface tools. Besides, older BTR was not flexible enough to work with different Tasks (tracking options) within each Run. In order to obtain and process the results from multiple BTR Runs, a User had to spend lots of time and efforts. BTR recent upgrades, which come with the new version BTR-5, make possible to run multi-parametric scans of different Scenarios of NBI operation - with small manual efforts and with higher results control, given a predefined list of Scenarios input. NBI geometry has become more flexible, allowing the combination of the Standard NBI approach and Free-Surfaces input, which can be taken from CAD design. New, Multi-Run approach implemented in BTR-5 offers to set the parameters for each BTR Task within a Scenario. This allows to have optimum statistics for detailed maps resolution, and to reduce the overall time for runs and results processing. BTR-5 has been used in the design studies of the Duct Liner Module (DLM) for ITER HNB. The DLM model was created by CAD and imported to BTR-5 in text format, combined with standard NBI components Configuration. The results of the power loads throughout different operation scenarios are shown. The conclusions are made on the DLM worst case scenario, and on the maximum power load for each DL surface.