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CVD Diamonds detectors

The use of polycrystalline CVD diamond for the detection of ionising radiation (including UV and X-ray) has been widely reported. Diamond has a unique combination of superior physical properties which make it the ideal candidate for photoconductive detectors replacing silicon in XUV astrophysical applications. Nowadays, the CVD technique makes available thick and large area polycrystalline films. A research team to investigate the properties of detectors using interdigitated electrodes on polycrystalline CVD diamond and similar devices has been formed several years ago together with the Dipartimento di Astronomia e Scienza dello Spazio of the University of Florence, the Dipartimento di Meccanica e Materiali of the University of Reggio Calabria and the Dipartimento di Ingegneria Meccanica of the University of Rome (Tor Vergata). The team has received funds by CNAA, MURST, and ASI.
During the past year we completed our investigations on polycrystalline CVD diamonds. Unfortunately, the results of these studies shows that this material is not suitable for imaging applications. In fact, the response of polycrystalline diamond detectors is not uniform over the area of the detector and they show long time constants and a response which varies with time. The homogeneity of single-crystal homoepitaxial CVD diamond and the absence of grain boundaries, with respect to polycrystalline films, holds out the promise to overcome all of these difficulties. so we decided to carry out some preliminary measurements on single-crystal diamond UV detector laboratory prototypes in order to test their performances. The results are very promising show very high gain values, shorter time constant and no evidence of persistent photocurrents. At the end of the year a research program to explore the potential of this material as well as the technological aspects connected to its astrophysical applications has been funded by MIUR.
Finally at the Catania Astrophysical Observatory we have completed the design and realization of the electronics to manage small prototypes of diamond pixel detectors. The electronics which, originally, was supposed to manage polycrystalline CVD diamond pixel detectors can be used without any problem when prototypes of single-crystal homoepitaxial CVD diamonds will be available.


next up previous contents index
Next: SPAD detector Up: Detectors Previous: CCD controllers   Contents   Index
Innocenza Busa' 2005-11-14