3D diamond detector tested at RBI
Stjepko Fazinic (RBI), Natko Skukan (RBI), Milko Jakšić (RBI), 01/12/2017
Alexander Oh (Univ. Manchester) and Ivan Sudic (RBI) at the RBI ion microprobe facility during the IBIC measurements (Image: Milko Jakšić, RBI)
In 2017, the ion micro-beam facility based at the Rudjer Boskovic Institute (RBI) in Zagreb, Croatia hosted testing of a 3D single crystal diamond detector.
The device, produced by a group led by Dr Alexander Oh from the University of Manchester, had its charge collection efficiency (CCE) tested at RBI under the Transnational Access programme offered by the AIDA-2020 project.
Compared to standard planar diamond detectors, studies have indicated that 3D diamond detectors offer higher levels of radiation hardness. As a result, researchers wishing to take advantage of this benefit in future designs, must test and characterise their materials and prototypes.
Using a 4.5 MeV proton micro-beam, researchers employed both ion beam induced charge (IBIC) and time resolved ion beam induced current (TRIBIC) mapping techniques. The tests considered two different 3D contact geometries, cubic and hexagonal cells, to ascertain whether their performances were comparable. This would also allow researchers to understand the cells’ charge sharing properties, which may influence the applications available with use of a particular cell type.
Following testing, the results showed that the detector has a good charge collection efficiency of 100% in active volume for both geometries. However, it was noted that the charge sharing between cells is stronger with a cubic contact geometry, with a reduction of 25% in hexagonal cells.
Current signals obtained with TRIBIC measurements were compared with simulations and are in good agreement. In the future, irradiated samples of the detector diamond will be tested to better understand the impact of radiation, which is important for both particle tracking and medical applications.
The results of the study were published in the journal Diamond and Related Materials [1] and further research is ongoing.