Position linearity and resolution of large position-sensitive silicon detector with a highly uniform thickness

Large two-dimensional position-sensitive silicon detectors (PSDs) with good position linearity, resolution and thickness uniformity have been developed. The PSDs have an effective area of 62 mm × 62 mm and a thickness of 500 μm. The non-linearity and position resolution for the whole sensitive area are found to be less than 0.26 mm in rms and 0.44 mm in fwhm, respectively, when an energy of 157 MeV is deposited in the detector and a shaping time constant of 12 μs is used in the pulse processing. The non-uniformity of detector thickness is ≤ 0.1% in rms. The PSDs recently developed are good enough to separate iron isotopes in a telescope aboard the GEOTAIL spacecraft scheduled to be launched at July in 1992.