Transcript S. Marti (ALIVABA a portable read-out system for Si detectors)

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).
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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
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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
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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.
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• 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).
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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.
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Custom made:
•DBs,
•Pitch adaptors
•and detectors
can be made on
requests.
One MB can drive up to
16 Beetle chip.
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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.
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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.
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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.
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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.
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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..
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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.
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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.
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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.
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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.
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Thank you for your attention
www.alibavasystems.com
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