Abstract
Abstract
In this paper, results are presented from the
characterisation of Redlen Technologies high-flux-capable Cadmium
Zinc Telluride (HF-CZT) hybridised to the HEXITECMHz
ASIC, a novel 1 MHz continuous X-ray imaging system. A 2 mm thick
HF-CZT HEXITECMHz detector was characterised on the B16
Test Beamline at the Diamond Light Source and displayed an average
FWHM of 850 eV for monochromatic X-rays of energy
20 keV. Measurements revealed a shift in the baseline of
irradiated pixels that results in a movement of the entire spectrum
to higher ADU values. Datasets taken to analyse the effect's
dynamics showed it to be highly localised and flux-dependent, with
the excess leakage current generated equivalent to per-pixel shifts
of ∼ 543 pA (8.68 nA mm-2) at a flux of
1.26×107 ph s-1 mm-2. Comparison to results
from a p-type Si HEXITECMHz device indicate this `excess
leakage-current' effect is unique to HF-CZT and it is hypothesised
that it originates from trapping at the electrode-CZT interface and
a temporary modification of the potential barrier between the CZT
and metal electrode.