Background: A 200 mm×200 mm two-dimensional positional sensitive detector(PSD) has been designd and constructed for the cold-neutron triple axis spectrometer(CTAS). The parameters of the PSD are necessary for evaluation and analysis of neutron scattering pattern obtained on CTAS and other instrument using PSD

mainly for the correction of angle and spectral shape due to the unequal solid angle and inhomogeneous efficiency of the flat PSD. Purpose: In order to obtain the working bias voltage

pixel size

spatial resolution

detection efficiency and its uniformity

a calibration method was proposed and tested for the PSD of CTAS. Methods: The calibration was carried out at the ATHOS three-axis spectrometer installed at the neutron guide No.1 of the 10-MW steady state reactor of the Budapest Neutron Centre. The focusing copper monochrometer provided well collimated(20’ divergence) neutron beam of wavelength equal to 0.572 nm with the second order equal to 0.286 nm. A black neutron detector having >99% efficiency at these wavelengths coated with boron shielding was used for efficiency test and a 0.5-mm wide Cd slit was used for the determination of pixel size and spatial resolution of the PSD. Results: The experimental results show that the working bias voltage is 4.2-4.4 kV

pixel size 0.32 mm(H&V)

the detector spatial resolution of 2.15 mm(H)×2.04 mm(V)

the detection efficiency of 90.47% and the efficiency uniformity better than 10%. Conclusion: The established method was successfully used in the PSD calibration

which can be extended to PSD R&D and data analysis of neutron spectrometer.