Setup for testing of diamond detectors in high temperatures
For testing of diamond detectors in high temperatures, in cooperation with the Division of Scientific Equipment and Infrastructure Construction (DAI) of our Institute and the Cracow University of Technology, two experimental chambers were created. The performance of diamond detectors, working in extreme conditions (high temperature and high neutron fluxes) in large thermonuclear devices, has to be tested. For this purpose, two test chambers have been designed and constructed.
Setup for diamond detectors thermal tests
Programable controllers of the experimental setup
In our department, diamond detector tests were performed for the ITER fusion device. The measurements have been carried out with conditions similar to ITER environment. Both chambers have been programmed to simulate the tokamak's baking (start-up) process and the normal operation of the fusion device. Below, examples of temperature cycles (so-called accelerated thermal tests) in the programmed controllers, for both chambers, are presented.
As a reference, for diamond detectors, triple alpha sources (239Pu + 241Am + 244Cm) were used. Each nuclide features one (main) energy line and the total result of the spectrometric measurement is shown below.
At the beginning of the detectors testing (before exposing to high temperatures), a reference measurement with the triple alpha source is carried out. Later on, every few temperature cycles, a verifying measurement is carried out to check whether the energy lines are "shifted" with respect to the reference recording. If the spectrum energy lines are shifted, broadened or they disappeared, the detector is submitted to a further verification analysis and examination under a microscope.
Examination of its internal structure allows to determine whether the detector has been damaged or its structure has been disturbed due to the influence of high temperatures. Below, a diagram of the electronic measuring system for standard measurements and checking, carried out every few temperature cycles, is shown.
