Boron Nitride layer as protective layer in X-ray tube

Purpose and goal

The project has shown that BN works as a stable insulating layer on thin carbon foils heated to glowing temperature in vacuum.

Results and expected effects

The project was more demanding and time consuming than expected to complete especially due to problems with the system for etching of the BN layer. Finally, the project was however successful and could show through experimental evaluation that BN is a candidate for insulating layers in future commercial carbon foils for metal vapor mitigation. The work with final development of such foils is now in progress.

Approach and implementation

Excillum supplied LiU with carbon foils that were deposited with BN. Back-side etching was complicated by the etching equipment of LiU being out of order for several months. Attempts were made to etch the foils at the Electrum lab instead but were not successful since the light samples moved in process. The equipment was finally repaired at LiU so that etching could be performed. Excillum could then evaluate the foils at high temperature. While waiting for the BN deposited foild, Excillum was working on its evaluation process using SiO deposited foils obtained separately from the project.