Calibration of the Position Sensitive Beam Monitor of the Heidelberg Dust Accelerator

Abstract

To ascertain a dust particle's trajectory a new developed position sensitive detector was implemented in the beam line of the Heidelberg Dust Accelerator. It allows to determine a dust particle's position without effecting its movement by using the principle of electric induction. This work describes the calibration method and its results that now can be used to map a detector signal to a particle position in the beam line. Additionally an idealised simulation was used to calculate the expected signals. The accuracy of the detector for various signal to noise ratios (SNR) and the charge detection limit was determined. As a secondary independent position measurement a segmented impact target was installed in the beam line to correlate a dust impact and a detector signal. The resulting calibration curve yielded to an estimate of the detector accuracy of about 0.3 mm based on a SNR of 20 dB. By evaluating the noise of the detector, the charge detection limit was determined to be 1.23 fC for particles passing through the center of the beam line. The detector simulation, calculated with the software programme Coulomb, was used to produce a calibration curve that represents the experimental results supportingl