development of electronics for radiation monitoring and...
TRANSCRIPT
Development of
electronics for radiation
monitoring and solid state
detector R&D Isidre Mateu Suau (EP-DT-DD)
Supervisors: Michael Moll, Federico Ravotti
FTEC 2nd workshop
27/04/2016
Outline
1. Activities in the Solid State Detector (SSD) team
2. Activities in the Irradiation Facilities (IRRAD) team
3. Short term & challenges
SSD team Part of EP-DT-DD section
Study of radiation damage on silicon detectors(part of RD50 collaboration)
Different test setups are maintained within the team, for
the characterization of silicon sensors before and after irradiation. Those include:
• Probe station for C-V, I-V characterization • Several setups featuring illumination of detectors
using lasers or radioactive sources to study charge
collection efficiency and distribution, electric field shape, homogeneity…
• Cryocooler to measure the temperature dependence of the leakage current Study of defects in silicon after irradiation
My activities…
Provide service to users (Maintenance and operation of the test setups)
Research activity in the frame of RD50.
• Involved in the “Acceptor removal” project (decrease in P+ doping concentration in silicon with irradiation)
Currently working to improve the accuracy of the temperature measurement in our cryocooler
TCT setup (laser induced pulses)
CV-IV probe station
Work on the cryocooler Purpose: measurement of the leakage current in a silicon diode as a function of the temperature
From 20K to room temperature with a controlled heating rate A calibrated temperature sensor is used as a reference Measured currents when heating up and cooling down don’t overlap Error in the temperature
measurement Main problem: bad thermal conductivity of our PCB substrate
~6K Sensor colder than DUT
when warming
up
Mounting of a silicon diode on the
cryocooler sample-holder
Measured current on a diode (Heating up/cooling down)
Design of a ceramic PCB
Dummy test with a ceramic PCB has given satisfactory
results I am currently designing a PCB adapted to our needs and
compatible with the rest of our setups
Design using Allegro suite Allegro coupled with Pspice simulations in order to study
the integrity of the laser induced pulses (sub-nanosecond regime)
PCB design - Simulated transmitted
pulse for different design options
Ceramic PCB test – measured current putting a
pt1000 in the place of a diode
Ceramic PCB test – mounting on the
sample holder
Outline
1. Activities in the SSD team
2. Activities in the IRRAD team
3. Short term & challenges
EP Irradiation facilities
Irradiation team (EP-DT-DD) maintains and
operates • IRRAD proton facility: T8 proton beam-line
(24GeV/c) at the CERN PS East Hall (bldg.
157) • Gamma irradiation facility (GIF++): Caesium
irradiator, located at SPS North Area Support to the EP department and CERN users in
planning irradiation experiments
http://ep-dep-dt.web.cern.ch/irradiation-facilities
My activities… Development of a portable readout system for a
radiation monitor in the frame of the RADMON
project Interface between the SSD team and IRRAD for
the irradiation of silicon sensors IRRAD proton facility
GIF++
RADMON project F. Ravotti thesis (2006) Characterization of sensors for radiation monitoring and design of
RADMON board carrying: • PIN sensors to measure displacement damage or non ionizing energy loss (NIEL) • MOSFET sensors (RadFET) to measure total ionizing dose (TID)
RADMON readout • Same scheme for all devices.
• Current implementation: o With basic laboratory testbenches (small experiments/irradiation tests)
o LHC experiments: dedicated (but complex) readout system embedded in the DCS.
G. Gorine (Bsc thesis) worked in the development of a portable, low cost readout system. A first prototype was produced but some issues were found: • Real performance of the power supply ≠ manufacturer datasheet
• Optimum reading of PIN diodes (within 50 ms) was not possible in all conditions.
HV 3
1
2
4
Portable readout system
RADMON board
1. Full characterization of the power supply, with special attention to the
ranges of interest for the readout of each sensor • Ripple, overshoot and time to settle were systematically measured, and
“Compliant region” plots were produced by setting thresholds for each
characteristic
• Requirement on the time to settle has to be relaxed from 50ms to 100ms for
the PIN diodes.
2. Optimization of the filters for each dosimeter • Simulation to try to reproduce the behavior of the power supply
• In particular, we want to minimize the amount of current injected to the PIN
diodes during short current pulses (e.g. damage to the devices)
3. Implementation of a readout protocol in the microcontroller 4. Finalization & test of the prototype in the EP facilities
RADMON project - Work plan
101
102
103
104
10-2 10-1 100 101 102
Io[uA]
Vo [V]
Compliant region (Ripple = 10%, Overshoot = 10%, Time to settle = 100ms)
REM LAAS BPW LBSD
Io = 25 mA
Vo є [1,10] V
Tr = 50 ms
Io = 1 mA
Vo є [0.5,80] V
Tr = 50 ms
101
102
103
104
10-2 10-1 100 101 102
Io[uA]
Vo [V]
Compliant region (Ripple = 5%, Overshoot = 5%, Time to settle = 3000ms)
REM LAAS BPW LBSD
Io = 100 µA
Vo є [3,10] V
Tr = 3000 ms
Io = 160 µA
Vo є [3.5,40] V
Tr = 3000 ms
Compliant region for PIN diodes Compliant region for RadFETS
Characterization
testbench
Outline
1. Activities in the SSD team
2. Activities in the IRRAD team
3. Short term & challenges
In the SSD team…
Finalize and produce ceramic PCB
New design of the cryocooler sample-holder and connections
RD50 workshop in June
In the IRRAD team…
Continuation of work with the RADMON reader
Participate with the IRRAD team in the irradiation run 2016 (starting
today!)
Experimental determination of the hardness factor of the proton irradiation
facility
Short term & Challenges