CVD grown monocrystalline diamond characterization and study for the application as a dosimeter. The project aim is also to design an ASIC readout electronic for single and matrix dosimeters.
The preliminary measurements show a very good linearity as function of the dose and a very good repeatability of the results on different samples both irradiated with gamma and electron beams.
The first release of the ASIC showed some problems due to leakage currents on the analog input pads.
A second release of the ASIC has been taken into account, to fix the leakage currents problem removing ESD protection from the analog pads. A new PAD leakage compensation circuit was designed. So the new release of the ASIC was developed with simulations and layout.
First measurment on the ASIC frontends showed that the leakage problems of the previous version was totally resolved. The leakeage current measured on the integrator capacitor is around 30 fA +- 15 fA.
Then the ASIC was tested connected with CVD diamond dosimeter in two different configuration: in the first one 9 channel from the ASIC was connected to 9 strips (250 um x 3 mm each) of metal on a single dosimeter (the strips was made with a photolitographic process); in the second one the ASIC was connected to an array of 2x2 diamond dosimeters.
With the first configuration is possible to scan an x-ray source or an UV pulsed laser source with submillimetric resolution, while the second configuration is usefull for monitoring beam used during therapy.