Asymmetries in Silicon Microstrip Response Function and Lorentz Angle

TL;DR

This paper investigates asymmetries in silicon microstrip detectors' response functions, revealing how these asymmetries affect measurements like the Lorentz angle and proposing a method to extract and correct for these effects using standard data.

Contribution

It introduces a novel approach to identify and quantify asymmetries in silicon microstrip response functions, improving measurement accuracy in particle detection.

Findings

Asymmetries cause a non-zero average in the center of gravity algorithm.

The proposed method effectively detects asymmetry parameters in simulations.

The response asymmetry varies linearly with the incident angle.

Abstract

An experimental set up, dedicated to isolate an error present in the $\eta$-algorithm, gave an unexpected result. The average of a center of gravity algorithm at orthogonal particle incidence turns out to be non zero. This non zero average signals an asymmetry in the response function of the strips, and introduces a further parameter in the corrections: the shift of the strip response center of gravity respect its geometrical position. A strategy to extract this parameter from a standard data set is discussed. Some simulations with various asymmetric response functions are explored for this test. The method is able to detect easily the asymmetry parameters introduced in the simulations. Its robustness is tested against angular rotations, and we see an almost linear variation with the angle. This simple property is used to simulate a determination of a Lorentz angle with and without the asymmetry of the response function.