The position response of the detector was investigated using a collimated "fan" beam of 60 keV gamma rays (Am241). The beam had width of 35 microns and was oriented both parallel to the set of strips being studied, then moved in a perpendicular direction across it, i.e. scanned across it. 

Response vs. position of a strip detector (2 mm strip pitch). The beam is scanned across the boundary between two x-strips (boron implant).  The count rate in the X14 strip in a energy window 58-62 keV drops as the beam moves over the edge of the strip (blue curve).  The count rate starts increasing in strip X15 (green curve) as the beam moves over it.  The red curve corresponds to a narrow region where charge is shared between the two strips, and the sum of the energy in measured in strips X14 + X15 falls inside the energy window. 

Similarly, the fan beam is scanned between two y-strips (Li drifted contacts).  Because of the contact technology, there is a wider gap between the Li strips in order to assure that the strips remain properly isolated.  Therefore, the region where charge is shared is somewhat wider.  The slight drop in counting rate in the red curve is caused by some events being lost when the energy in either strip Y5 or Y4 is below a discriminator threshold set at around 10 keV, thus a small amount of signal is occasionally lost. 

For a more detailed discussion, please download one of our  preprints.

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