THE DETECTION OF HEAVY-IONS WITH PIN DIODES

The pulse height defect (PHD) and the resolution (ΔE) of a low-cost PIN photodiode (Hamamatsu Model S 1223-01) have been studied for 11B (0.2-16.2 MeV), 35Cl (1.0-8.2 MeV) and 81Br (0.5-8.0 MeV) ions, and found comparable to those of ORTEC silicon surface barrier detectors. The major contribution to the difference in performance of the PIN diode may come from the surface dead-layer which was measured to be 90 ± 11 nm. The dependence of diode properties on the bias voltage shows that even at 0 V the relative pulse height is ≥95% of the value of saturation which is attained within 5 V. The relative resolution (ΔE/E) is nearly constant for all bias values up to 30 V (maximum reverse bias). Some preliminary results on the effect of radiation dose on the leakage current are also presented. These results demonstrate that the low-cost PIN diode can be successfully used as a charged-particle detector in applications such as ion beam analysis (RBS, HIRBS, ERD) and space technology. © 1990.