Transcript A readout system for microstrip silicon sensors

A portable readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
A portable readout system for
microstrip silicon sensors
(ALIBAVA)
Bernabeu, J.a, Casse, G.b, García, C.a, Greenall, A.b, Lacasta, C.a, Lozano, M.c, Marco-Hernández,
R.a, Martí i García, S.a, Martinez, R.b Miñano, M.a, Pellegrini, G.c, Smith, N. A.b, Ullán, M.c
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Instituto de Física Corpuscular (IFIC), Universidad de Valencia-CSIC,Valencia, Spain.
Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK.
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Instituto de Microelectrónica de Barcelona, IMB-CNM, CSIC, Barcelona, Spain
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
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A portable readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Outline
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Motivations.
System requirements.
System architecture.
Daughter board:
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Mother board:
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Block diagram.
Beetle chip.
Fan-ins.
Block diagram.
FPGA logic.
System operation.
PC software characteristics.
Calibration measurements.
Measurements with laser setup.
Measurements with β source.
Conclusions and outlook.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
2
A portable readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Motivations
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Study the main properties of highly irradiated microstrip silicon sensors: SLHC.
Particularly the collected charge: detector performance.
Difficulty for obtaining this type of measurements:
– Required equipment is expensive.
– A large number of channels has to be measured.
– There is minimum standardization.
Testing with an electronic system as similar as possible to those used at LHC
experiments: a LHC front end readout chip should be used.
Analogue readout is preferred for accurate pulse shape reconstruction.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
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A portable readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
System requirements
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A compact and portable system.
The system will be used with two different laboratory setups:
– Radioactive source: external trigger input from one or two photomultipliers.
Alternatively a digital trigger input as well (from an external discriminator).
– Laser system: synchronized trigger output generated internally for pulsing an
external excitation source.
The system should contain two front-end readout chips (Beetle chip used in LHCb) to
acquire the detector signals.
USB communication with a PC which will store and will process the data acquired.
System control from a PC software application in communication with a FPGA which
will interpret and will execute the orders.
Own supply system from AC mains.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
4
A portable readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
System requirements
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A compact and portable system.
The system will be used with two different laboratory setups:
– Radioactive source: external trigger input from one or two photomultipliers
– Laser system: synchronized trigger output generated internally for pulsing an
external excitation source.
The system should contain two front-end readout chips (Beetle chip used in LHCb) to
acquire the detector signals.
USB communication with a PC which will store and will process the data acquired.
System control from a PC software application in communication with a FPGA which
will interpret and will execute the orders.
Own supply system from AC mains.
The main goal is
reconstructing the
analogue pulse shape from
the readout chip front-end
with the highest fidelity
from the acquired data.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
5
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
System architecture
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Two main parts: software part (PC) and
hardware part.
Hardware part: a dual board based
system.
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Mother board intended:
• To process the analogue data that
comes from the readout chips.
• To process the trigger input signal in
case of radioactive source setup or to
generate a trigger signal if a laser
setup is used.
• To control the hardware part.
• To communicate with a PC via USB.
Daughter board :
• It will be a small board.
• It will contain two Beetle readout
chips
• It will have fan-ins and detector
support to interface the sensors.
Software part:
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It will control the whole system
(configuration, calibration and acquisition).
It will generate an output file for further
data processing.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
6
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Daughter board: block diagram
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Two Beetle readout chips in parallel mode
(256 input channels).
A buffer stage for each analogue output of
the Beetle chips:
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Differential current to differential voltage
buffer (AD8132) implemented.
Buffered signals are sent to the mother
board with impedance matched.
Fast control (LVDS signals) and slow
control (I2C bus) shared by Beetle chips.
A thermistor (NTC) for sensing the
temperature close to the Beetle chips.
Low voltage DC level (5 V) for Beetle
chips (2.5 V) and buffer stage power
supply (3 V).
High voltage DC level for silicon
detector(s) bias through a power lemo
connector.
Fan-ins and detector board.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
7
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Daughter board: Beetle chip
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Readout chip developed at ASIC
laboratory of the University of
Heildelberg.
Front-end output signal: signal that
will be reconstructed from analogue
readout onto one port.
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This signal is sampled into the
analogue pipeline (128x187 cells)
with the frequency of the Beetle
chip clock (40 MHz).
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Vp = kQ. Tp ~ 25 ns. Total pulse
length about 65-70 ns.
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The analogue pipeline
programmable latency fixed to 128
CLK cycles (3.2 µs).
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The TRIGGER signal will have to
be active 128 CLK cycles (3.2 µs)
after a particular front-end signal
point of interest has been sampled.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
8
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Daughter board: Beetle chip output format
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Analogue output format: single readout
onto one output port.
Readout: 16 bits header + 128
analogue multiplexed channels.
Channel width of 25 ns (40 MHz clock).
DataValid signal for readout detection.
Output dynamic range: linear up to ~
±110000 e-.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
9
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Daughter board: detector support
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Fan-ins:
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Text-box:
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Three fan-ins: chip fan-in, intermediate fanin and detector fan-in.
Each fan-in has pads of 80 um pitch not
staggered and 10 rows for multiple wire
bonding.
Daughter board and detector boards are
fixed to base plate for facilitating wirebonding.
Two flavours of detector board exist:
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Small, for 1cm2 sensors (board dimensions
~37mm x 32mm).
Large, for 1cm x 3cm sensors (board
dimensions ~37mm x 50mm).
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
10
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: block diagram
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Signal conditioning block transforms the
differential voltage analogue input signal
from each Beetle to:
– Drive an oscilloscope: single ended
signal.
– Drive ADC: differential input shifted
signal.
ADC (one for each Beetle):
– 10 bit flash type with a sample rate
of 40 MHz (MAX1448).
– Nominal resolution of 1 mV (output
signed code, 9 bits plus 1 sign bit).
– Dynamic range will be ±512 mV.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
11
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: block diagram
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In case of radioactive source setup for
obtaining a time stamp of each trigger.
Trigger conditioning:
– Leading-edge discrimination for two
photomultiplier analogue input signals.
– Level conversion for an auxiliary signal
(current or voltage).
– Two dual LVPECL high speed
comparators (MAX9601).
– Four programmable voltage thresholds:
generated with a quad 12 bits DAC
(DAC7614).
TDC: measurement of t between input trigger
and a periodic reference signal (100 ns).
– A TDC integrated circuit (TDC-GP1).
– Nominal resolution: 600 ps.
– 100 ns dynamic range.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
12
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: block diagram
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In case of laser setup.
A synchronised output trigger signal (TRIG
OUT) will be generated to drive a laser source
to reconstruct the Beetle front-end pulse
shape.
Programmable delay circuit (3D7428):
– Resolution: 1 ns.
– Range: up to 255 ns.
– Programmed by FPGA by serial
interface.
Following this block a 50 Ω driver will be
incorporated for driving a pulse generator
input.
Programmable delay
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
13
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: block diagram
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SDRAM (256 Mb): for acquisition data
storage.
TEMPERATURE CONVERTER: NTC
thermistor signal digitalization.
SLOW CONTROL: generated directly by the
FPGA. External pull-up resistors for SDA and
SCL lines.
FAST CONTROL:
– LVDS driver (DS90LV47A) and LVDS
receiver (DS90LV48A).
– Six CM noise suppressor chokes
(23Z105SM).
USB: USB controller (FT245R) for USB to
FIFO parallel (8 bits) bidirectional data
transfer.
SUPPLY SYSTEM:
– DC input (5V) from AC adapter.
– Digital levels from 2 DC-DC converter
(1.2 V and 3.3 V) + 1 linear regulator (2.5
V).
– Analogue levels from DC-DC converter
(±5V) + 1 linear regulator (3.3V).
– Daughter board level from DC-DC
converter (5V).
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
14
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: FPGA logic
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FPGA hardware:
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FPGA logic operation:
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Xilinx Spartan-3 (XS3400-PQ208)
clocked at 40 MHz.
External reset push button.
On-system configuration PROM memory.
Two LEDs for system status.
Custom logic blocks (VHDL) for low level
hardware control.
Centralized control from a CFSM.
FPGA logic blocks:
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A CFSM (Central Finite State Machine)
will control the different blocks depending
on the current state of the system.
Radioactive source: the DAC CONTROL,
TRIGGER IN and TDC CONTROL will be
used for processing the trigger inputs
and obtaining a time stamp of each
trigger.
Laser setup: the TRIGGER OUT block
will generate the output trigger signal and
will control the programmable delay
circuit.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
15
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: FPGA logic
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FPGA logic blocks:
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ADC CONTROL: readout of the digitized
data frames when the input DataValid
(fast control) signal will be active. This
digitized data will be stored in a internal
FIFO RAM.
BEETLE FAST CONTROL: generation of
fast control signals (Clk, Trigger,
Testpulse and Reset) depending on the
state of the system.
BEETLE SLOW CONTROL: I2C master
controller for writing/reading the Beetle
internal registers (slow control) for
configuration.
SDRAM CONTROL: implements a
controller for interfacing the SDRAM and
the CFSM.
USB CONTROL: interface between the
USB controller and the CFSM.
CLOCK GENERATOR: required internal
clock and reset signals generation.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
16
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: FPGA logic
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FPGA logic:
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The CFSM and SDRAM CONTROL have
been implemented with an embedded
system (soft processor + SDRAM
peripheral).
Soft processor: Microblaze (32 bits
RISC) at 40 MHz.
SDRAM controller included as standard
peripheral for the Microblaze.
ARBITRER : custom block of registers
for communication between the
embedded processor and the custom
logic blocks.
FSLs (Fast Simplex Links): unidirectional
FIFOs for fast communication between
the ARBITRER and the Microblaze.
The functionality of the system is
programmed as a standard C program
in the processor (firmware): great
flexibility for changes.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
17
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: system operation
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RESET:
– System initialization.
– With a power on, with an external reset
or by software reset.
WAITING:
– The system will wait for an order coming
from the PC software to go to another
state.
BEETLE CONFIGURATION:
– Beetle chips configuration registers
programming.
CALIBRATION:
– System calibration by the Beetle internal
test pulse generator.
– Known amplitude readouts will be
acquired.
TRIGGER IN CONFIGURATION:
– DAC voltage thresholds will be
programmed.
– Trigger inputs scheme will be configured.
LASER SYHRONIZATION:
– The system will be synchronized for the
Beetle front end pulse reconstruction.
– By delaying the TRIG OUT signal in 1 ns
steps.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
18
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Mother board: system operation
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PEDESTALS, RS or LASER ACQUISITION:
– A programmable number of readouts will
be able to be acquired (up to 64776) and
stored in the SDRAM.
– PEDESTALS: For each event a Beetle
chips readout (256 by 16 bits) and a
temperature readout will be stored in the
SDRAM. No charge acquired with Beetle
chips.
– RS: For each event a Beetle chips
readout (256 by 16 bits), a TDC readout
(32 bits) and a temperature readout will
be stored in the SDRAM.
– LASER: For each event a Beetle chips
readout (256 by 16 bits) and a
temperature readout (16 bits) will be
stored in the SDRAM. The TRIG OUT
frequency will be 1 KHz.
PEDESTALS, RS or LASER READING:
– The last type of acquisition will be read
from SDRAM and data will be sent to PC
by USB.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
19
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
PC software
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Functions:
– Control the whole system
(configuration, calibration and
acquisition).
– User interface with the system
(GUI).
– Generation of information (output
files).
Two software levels:
– Low level for software/mother board
communication by USB: VCP
(virtual com port) driver (2.4 Mb/s)
used.
– High level: GUI and output file
generation for further processing.
Programming language: C++
Operating system compatibility:
– Linux version fully operational.
– Windows beta version.
There are also macros for ROOT in
order to process the data acquired with
the software.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
20
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Calibration measurements: n-type detector
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Data acquired from
calibration acquisition.
Beetle chip 1 (channels 1128) without detector.
Non-irradiated n-type
detector connected to
Beetle chip 2 (channels 129256).
First 14 and last 14 channels
of Beetle 2 without detector:
detector of 100 channels.
Some channels does not
operate due ‘shorts’ at the
bonds: reduced gain.
This data is used to calculate
the ADC/electrons rate for
each channel.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
21
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Calibration measurements: p-type detector
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Data acquired from
calibration acquisition.
Beetle chip 1 (channels 1128) without detector.
Non-irradiated p-type
detector connected to
Beetle chip 2 (channels 129256).
This data is used to calculate
the ADC/electrons rate for
each channel.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
22
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Measurements with laser setup: n-type detector
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Data acquired by means of a
laser scan.
Non-irradiated n-type
detector connected to Beetle
chip 2 (same conditions as
on calibration).
Vbias = 200 V (full depletion).
Laser light:
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Laser scan:
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Wavelength: 1060 nm (near
infrared).
Laser energy of photons:
1.17 eV.
Scan delay range: 10401140 ns.
Delay step: 1 ns.
100 samples per step.
Some channels does not
work due to bad bonds.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
23
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Measurements with laser setup: p-type detector
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Data acquired by means of a
laser scan.
Non-irradiated p-type
detector connected to Beetle
chip 2 (same conditions as
on calibration).
Vbias = -100 V (full depletion).
Laser light:
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Laser scan:
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Wavelength: 1060 nm (near
infrared).
Laser energy of photons:
1.17 eV.
Scan delay range: 10401160 ns.
Delay step: 1 ns.
100 samples per step.
All channels work correctly.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
24
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Measurements with β source: n-type detector
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Acquisition with β source
(90Sr).
Non-irradiated n-type
detector connected to
Beetle chip 2 (same
conditions as calibration).
Vbias = 200 V (full
depletion).
Acquisition of ~ 19000
events (triggers):
– Trigger input from one
photomultiplier.
– Threshold: -40 mV.
Some channels are noisy
due to bad bonds.
Pulse peak charge
corresponding ~ 1 mip
(24810 e-).
Noise: ~ 1200 e-.
Common mode variations
(σ = 5.88 counts) corrected
by software.
SNR for peak voltage: ~
21.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
25
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Measurements with β source: p-type detector
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Acquisition with β source
(90Sr).
Non-irradiated p-type
detector connected to
Beetle chip 2 (same
conditions as calibration).
Vbias = -100 V (full
depletion).
Acquisition of 20000
events (triggers):
– Trigger input from one
photomultiplier.
– Threshold: -40 mV.
All channels working.
Pulse peak charge
corresponding ~ 1 mip
(26940 e-).
Noise: ~ 1200 e-.
Common mode variations
(σ = 8.9 counts) corrected
by software.
SNR for peak voltage: ~
22.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
26
A readout system for microstrip silicon sensors (ALIBAVA)
3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April,
Barcelona, Spain
Conclusions and outlook
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The readout system has been developed and is fully operational.
The system can operate with different types and different sizes of microstrip detectors:
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The system is designed to work with a radioactive source setup and laser setup: useful
for comparing results with the same detector.
The system has been tested with laser setup and a β source:
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n-type.
p-type.
Up to 256 input channels.
Two flavours of detector boards to accommodate detectors of different sizes.
It works correctly.
With p-type and n-type detectors.
SNR ~ 20 with non-irradiated detectors: there is room for irradiated detectors.
Currently, there is a software Linux version: in the near future, there will be a Windows
version for the software (currently debugging a beta version).
Data acquired with the system can be easily processed using ROOT framework: some
macros already developed.
System is ready for production and distribution (motherboards and daughterboards in
stock). Production and assembly under demand.
Future work: upgrade of the system for testbeam acquisition by synchronizing various
ALIBAVAs.
Ricardo Marco-Hernández
IFIC(CSIC-Universidad de Valencia)
27