Preamplifiers and high voltage supply

The preamplifiers used for the TIARA detectors will use a design developed at Paisley as an extension of an original Oxford design that has been used successfully for many years by the Charissa collaboration. The new preamplifiers have been adapted specifically for use with the new CAEN N568B amplifiers that will be used for TIARA. The preamplifiers will be packaged in double-width NIM modules by adapting a design originally developed at Birmingham. The performance of the preamplifiers in experiments will be monitored and it is planned to continue development of the design as more experience accumulates. Each preamplifier module has 16 preamplifiers inside and the inputs and outputs are all brought out to Lemo connectors, which have been found to give the most flexibility in adapting to different systems. The bias voltage supply to the silicon detectors will be provided by a programmable system that allows the leakage current to be monitored and compensated if necessary. A suitable system is the CAEN System 127 High Voltage mainframe, with plug-in modules such as the A-635 which can provide four channels of independent biases per module, up to 200V/40$\mu$A.