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A radiation sensor characterisation system in a box INTRODUCTION • The ALIBAVA System is conceived to measure ionising radiation with radiation detectors, providing high sensitivity to small signals, high position resolution and high speed. Ion and photon counting also possible. • These measurement needs where in common among the Particle Physics groups of the University of Liverpool, IFIC-Valencia and the Radiation Detector group of the CNM-IMB in Barcelona. • The three institutes have developed this scientific instrument: ALIBAVA (A Liverpool, Barcelona Valencia development). 2 Elements of the system: • Detector board (DB); houses the front end electronics and the drivers • Mother board (MB): housing the DAQ and the drivers for communication with the PC/Laptop. • Software: for system configuration, data acquisition, and analysis 3 The frontend electronics is a low noise ASIC with 128 input channels and a clock speed of 40MHz. • Originally designed by the ASIC laboratory of the University of Heidelberg and the Max-PlanckInstitute for Nuclear physics for the LHCb experiment. • It is used by the LHCb Vertex Detector (VELO), the Silicon Tracker and the RICH. • Adapted for mip tracking and measurement with silicon detectors, ions and photon counting, readout of multi-anode photomultipliers. • It is a fast readout electronics clocked at 40MHz. It can be used in analogue or binary mode. • The chip can deal with positive and negative signals • The radiation hard design can tolerate doses in excess of 100Mrad. Details on chip at: http://www.kip.uni-heidelberg.de/lhcb/index.html 4 The detector board (DB) The DB typically hosts two Beetle ASICs, the Pitch Adapters (PA) for routing the readout and bias lines to the sensitive element (detector) and the line drivers to transfer the signal and commands between the ASICs and the mother board. The 2 ASICs can readout 128 channels each. They can be coupled to sensors with input capacitance up to several tens of pF. 5 • The system can read out a wide range of semiconductor detectors. • Customised solutions to specific needs (various geometries of the detectors, multi-chip boards for larger number of channels...). • Many ALIBAVA boards can be integrated to provide a multi-plane system (for reconstructing the track of the ionising radiation or for improved imaging). 6 Custom DB A novel 2D position-sensitive microstrip detector, where the resistive charge division method was implemented by replacing the metallic electrodes by slightly resistive polycrystalline silicon electrodes, can be read out by a customized version of the Alibava DB. 7 Custom made: •DBs, •Pitch adaptors •and detectors can be made on requests. One MB can drive up to 16 Beetle chip. 8 Mother Board (MB) 1) Signal conditioning 2) Triggering and timing block 3) Laser support block 4) FPGA The mother board (MB) arbitrates the communication between the PC and the DB. The core of the MB is a FPGA block that is composed of a FPGA (Spartan 3, Xilinx) that controls hardware and commands and synchronises the readout. The board includes line driver amplifiers, 2 ADCs (10 bits) clocked at 40 MHz, a TDC for signal shape reconstruction, comparators and coincidence for login handling of the trigger. The data passing to and from the computer is performed through a USB controller. The DC power needed by the MB and the DB are generated by DC-DC converters and LDO regulator. 9 The Mother Board The MB also provides a synchronised and programmable output trigger signal to drive a pulsed laser system. We are developing a laser pulsed with internal driver to deliver short (1 ns rise time) pulses. Wavelengths of 660, 980 and 1060 nm will be the available standards. 10 SOFTWARE Complete software package connect and get results! included: Software includes communication driver to the system, configuration software and a full analysis package. Full software with auto-install. Everything is adjusted by default, no need to deal with complex readout electronics. The user-friendly analysis package shows graphically the data readout and presents the collected charge on the radiation detector as well as electronic parameters (gain, noise, uniformity, etc.). Software guide and FAQ included. 11 SCIENTIFIC APPLICATIONS The capacity of measuring small signals with low noise at LHC clock speed make this system particularly favoured by groups that are studying the radiation tolerance of silicon detectors. In particular, the development of the ALIBAVA system has been supported by CERN-RD50 (Radiation hard semiconductor devices for very high luminosity colliders) and it is being used by more than 20 member institutes of this collaboration. 12 SCIENTIFIC APPLICATIONS A number of valuable measurements have been performed to demonstrate the ability of n-side readout silicon sensors to operate after the extreme doses expected in the inner layers of the LH-LHC.. 13 EDUCATIONAL APPLICATIONS It has been used for the extremely successful detector school at CERN in 2011 (Excellence in Detectors and Instrumentation Technologies, CERN, January 2011, http://edit2011.web.cern.ch/e dit2011/) encouraging us to develop a dedicated educational version. 14 Educational: EXAMPLES • To observe the noise of a silicon strip detector as a function of bias voltage. • To observe the signal spectra due to a minimum ionising particle in a silicon detector and demonstrate the Landau distribution shape of collected charge. • To observe the physical size of a charge cluster from a minimum ionising particle and relate this to the position resolution of the detector. 15 MORE INSTRUMENTS Sophisticated scientific instruments: particle telescope. A number of DB and MB can be used for more complex instruments required e.g. for tracking. A controller board is used (Master Board) and the communication speed to the control PC is increased by using a Ethernet connection. 16 SUMMARY The system is used by over 30 particle physics institutes in Europe and USA. It has been developed to fulfil the research needs of the RD50 collaboration at CERN (http://rd50.web.cern.ch/rd50/), many new uses have been developed. It is a very valuable tool for educational training. A significant number of scientific publications in refereed international journals and presentation to conferences (clearly including the NSS-MIC series) has been and are being produced with our system. 17 Thank you for your attention www.alibavasystems.com 18