Abstract
Edgeless radiation detector has gained increased
attention due to its superiority in the defect-free edge
fabrication and the capability to minimize the
insensitive area at the detector edge. The doped edge in
the edgeless detector is at the same potential with the
back plane and causes a local distortion of the electric
field at the detector edge. The deformed electric field
alters the charge collection of the edge pixel and leads
to an inaccurate charge interpolation. To study the
influence of active edges on the response of edge pixels,
we used an advanced X-ray based 3D spatial mapping
technique to visually show the charge collection volumes
of pixels. Various edgeless detectors with diverse
polarities, thicknesses and edge-to-pixel distances were
investigated. For the n-on-p (n+/p-/p+) edgeless
detector, the mapping shows that the p-spray isolation
method has the advantage of achieving a greater sensitive
edge region compared to the p-stop method. And the p-on-p
(p+/p-/n+) edgeless detector, reported for the first
time, functions for both spatial and energy signals. The
n-type edgeless detectors were studied together with a
standard Medipix detector with the guard ring design. The
results show that the edgeless detector is capable of
maximally utilizing the edge region of the detector as
the charge sensitive volume, while the standard Medipix
detector has still vast insensitive region at the edge.
The X-ray spectroscopic measurements with 241Am and 55Fe
sources performed on all detectors gives a similar
conclusion and proves the 3D spatial mapping results.
Original language | English |
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Article number | C04004 |
Number of pages | 9 |
Journal | Journal of Instrumentation |
Volume | 9 |
DOIs | |
Publication status | Published - 2014 |
MoE publication type | A1 Journal article-refereed |
Event | 15th International Workshop on Radiation Imaging Detectors, IWORID 2013 - Paris, France Duration: 23 Jun 2013 → 27 Jun 2013 |