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arXiv · 1708.07931

A GEM readout with radial zigzag strips and linear charge-sharing response

Aiwu Zhang·Marcus Hohlmann·Babak Azmoun·Martin L. Purschke·Craig Woody
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Abstract

We study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures are implemented on PCBs and on a flexible foil and are tested using a 10 cm by 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Angular resolutions of60-84 urad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 um.

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Aiwu Zhang, Marcus Hohlmann, Babak Azmoun, Martin L. Purschke, Craig Woody. 2017-08-26. A GEM readout with radial zigzag strips and linear charge-sharing response. https://doi.org/10.1016/j.nima.2017.12.074

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