5月28日 Boronisation procedure by deuterated diborane at ASDEX Upgrade

报告题目：Boronisation procedure by deuterated diborane at ASDEX Upgrade

报告人：Dr. Volker Rohde （德国 IPP）

报告时间：2025年5月28日 上午 9:30-11:00

报告地点：EAST控制室三楼会议

主持人：丁锐

报告人简介：

Dr.Volker Rohde is currently the group leader for vacuum and wall conditioning at the Max Planck Institute for Plasma Physics (IPP) in Garching, Germany, where he has been worked since 1993. His research focuses on plasma-wall interactions and the development of advanced conditioning techniques for fusion devices, particularly the ASDEX Upgrade tokamak. He has authored or co-authored over 460 publications, making substantial contributions to the field of nuclear fusion research.

报告摘要：

Conditioning of the plasma-facing surfaces (PFSs) in fusion devices is essential for reliable plasma operation. In full tungsten ASDEX Upgrade (AUG), boronization by a glow discharge in He with 10% of deuterated diborane is used as standard wall conditioning technique. Recently the PFSs in ITER were changed to full tungsten, which triggered strong interest in wall conditioning techniques currently used at full metal fusion devices.

To fulfil actual European safety regulations the boronization system was renewed in the last years. Now an automatic procedure allows to apply boronizations reliable during a working day. The main ideas and procedures of the new system are discussed.

Analysis of the existing data from boronizations were presented at the recent PSI conference. To fill the knowledge gaps, new diagnostics such as witness samples, quartz microbalance monitors (QMB) and manipulator systems were installed or activated. QMBs are used to measure the layer thickness during the coating process. This allows collecting data for different glow anode configurations without venting AUG. A code was developed to estimate the position and number of anodes required for boronization of ITER. To benchmark this code a coating with only 2 active anodes was performed in AUG. From the QMB data, a reduction of a factor of two of the layer thickness at a position close to a non-active anode was found, in qualitative agreement with the simulations, although the layers are much thicker than predicted.Samples made of different materials exposed during the boronization were used to confirm the deposition.