Effects in B–doped KDP crystals irradiated with neutrons of large spectra energy

The results obtained for the r63 electro-optic coefficient of B-doped and undoped KDP (KH2PO4) crystals irradiated with neutrons (including thermalized neutrons) produced by scattering of 30 Mev cyclotron protons on a target of Ta201, are presented and compared to those obtained for non-irradiated doped and undoped crystals. The B-doped (H3BO3, Na2B4O7 and Li2B4O7) crystals were obtained by the conventional growth method by temperature decrease with 1 wt % dopant concentration in solution. The thermal neutron flux was around ϕ = 1. 1010 n/cm2 s. Pulses of ∼15 μs long, in damped oscillatory mode (V= 8 kV, τ=1.95 μs) were used for the electro-optic measurements. A Pockels cell, a photomultiplier, a He-Ne laser (λ=632.8 nm, 5 mW, linearly polarized) and a Tk 720 A oscilloscope complete the experimental setup. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)