Low-Noise Charge Preamplifier for Electrostatic Beam Position Monitoring Sensor at the ELENA Experiment

The Extra Low ENergy Antiproton ring (ELENA) is a synchrotron under construction at CERN aimed to decelerate the antiprotons from the existing Antiproton Decelerator (AD) to an energy of 100 keV. The orbit measurement of the beam is accomplished by 20 electrostatic Beam Position Monitoring (BPM) sensors to measure complete orbits every 20 ms with a resolution of 0.1 mm for intensities in the range of 1-3 x 107 charges. For the conditioning of the pick-up signals from the BPMs a low -noise charge amplifier has been purposely designed and is under testing. The circuit must feature a bandwidth of 40 MHz and an equivalent input voltage noise spectral density of 0.4 nV/ Hz for a sensor capacitance Cs of about 26 pF. After amplification, the sum and difference signals are analogically derived and sent over 50 m cables to further blocks for digitalization and processing. (C) 2015 article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ric-nd/4.0/) Peer-review under responsibility of the organizing committee of EUROSENSORS The Authors. Published by Elsevier Ltd. This is an open access