J. Phys. IV France
Volume 133, June 2006
Page(s) 951 - 953
Publié en ligne 16 juin 2006
Inertial Fusion Sciences and Applications 2005
J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 951-953

DOI: 10.1051/jp4:2006133191

Recovery of CVD diamond detectors using laser double pulses

L.S. Dauffy1, R.A. Lerche1, G.J. Schmid1, J.A. Koch1 and C. Silbernagel2

1  Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
2  Bechtel Nevada Calibration Facilities, Livermore, CA 94551, USA

A $5 \times 0.25$ mm Chemical Vapor Deposited (CVD) diamond detector, with a voltage bias of +250 V, was excited by a 400 nm laser (3.1 eV photons) in order to study the saturation of the wafer and its associated electronics. In a first experiment, the laser beam energy was increased from a few tens of a pJ to about 100 ${\rm\mu}$J, and the signal from the diamond was recorded until full saturation of the detection system was achieved. Clear saturation of the detection system was observed at about 40 V, which corresponds with the expected saturation at 10% of the applied bias (250 V). The results indicate that the interaction mechanism of the 3.1 eV photons in the diamond (E $_{\rm bandgap} =
5.45$ eV) is not a multi-photon process but is linked to the impurities and defects of the crystal. In a second experiment, the detector was irradiated by a saturating first laser pulse and then by a delayed laser pulse of equal or smaller amplitude with delays of 5, 10, and 20 ns. The results suggest that the diamond and associated electronics recover within 10 to 20 ns after a strong saturating pulse.

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