A DEPFET Based Beam Telescope With Submicron Precision Capability

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> For the detection of secondary vertices of long lived particles containing bottom and charm quarks at the International Linear Collider (ILC), a DEPFET pixel detector is one of the technologically favored options. In a DEPFET sensor a MOSFET pixel detector is integrated on a sidewards depleted silicon bulk sensor, thus combining the advantages of a fully depleted silicon sensor with in-pixel amplification. DEPFET pixel matrices have been characterized in a high energy particle beam. Since the DEPFET is a very high precision device, given its large <formula formulatype="inline"><tex>${\rm S}/{\rm N}$</tex> </formula> (<formula formulatype="inline"><tex>$&gt; 100$</tex></formula>) and small pixel size (36<formula formulatype="inline"><tex>$\, \times 22 ~\mu {\rm m}^{2}$</tex></formula>), a DEPFET based pixel telescope consisting of 5 DEPFETs has been developed. The uncertainty on the predicted position for a device under test (DUT) positioned inside the telescope was found to be 1.4 <formula formulatype="inline"><tex>$\mu{\rm m}$</tex></formula> with the existing device, due to the limited performance of two of the five DEPFET planes. A DEPFET telescope built of 5 modules equivalent to the best plane presented here, would have a track extrapolation error as low as 0.65 <formula formulatype="inline"><tex>$\mu{\rm m}$</tex></formula> at the DUT plane. </para>