Response of Si p-i-n diode and Au/n-Si surface barrier detector to heavy ions

Pulse height versus energy calibrations of a Si p-i-n diode and a Au-/n-Si surface barrier detector have been studied for heavy ions with atomic number (Z(1)) from 3 to 79 in a range from 0.1 to 0.8 MeV per nucleon as a function of bias voltage and detector tilting angle. The detector response is simultaneously measured using a time of flight-energy elastic recoil detection analysis set-up with recoils produced over a wide energy range from a thick target of each element. Prior to impinging on the Si detector, the individual recoil is tagged by its energy determined from the time of flight and tabulated isotopic mass. For both detectors, the pulse height-energy calibration for recoils with a given Z(1) is described well by a linear relationship with small systematic deviations. The linear-fit parameters show similar, but not identical dependence on both Z(1) and bias voltage (collecting field strength) for the surface barrier detectors and the p-i-n diode. These results suggest that the efficiency of electron-hole pair collection is markedly dependent on the different electric field configurations for the two detector structures.