Performance of 5-𝜇mPIN diamond diodes as thermal neutron detectors

Diamond PIN diodes with an approximately 5-𝜇m thick i-layer and coated with a thin boron nitride (BN) layer have been tested with a thermal neutron beam. For a flux of 4.4 °¡ 106 n/s/cm2, count rates were on the order of 30–100 counts per second depending on the thickness of the BN neutron converter layer. Pulse height spectra showed features associated with 𝛼 and 7Li fission products consistent with the thickness of the BN layer. An irradiation test with a 1 MeV neutron equivalent fluence of 1015 n/cm2 showed no significant alteration in the count rate of the tested detector.

Read More

UV laser induced changes to morphological, optical and electrical properties of conductive nanocryst

The possibility of laser induced variation of optical and electrical properties of conductive nanocrystalline diamond (CNCD) films has been demonstrated. The films were produced by microwave plasma chemical vapor deposition (MPCVD) from CH4:H2:N2 gas mixtures. The films were irradiated in air with 20 ns pulses of an ArF excimer laser (λ = 193 nm). It was found that low laser pulse intensity (~0.05 J/cm2), well below film surface graphitization (~0.3 J/cm2) and nanoablation (~0.08 J/cm2) thresholds, induces changes of the film properties. The effect requires multiple pulsed irradiation and results in a decrease of the film electrical conductivity, which is accompanied by optical bleaching of the diamond film absorption.

Read More