1. Development of electronics for radiation monitoring and solid state detector R&D
Isidre Mateu Suau (EP-DT-DD)
Supervisors: Michael Moll, Federico Ravotti
FTEC 3rd workshop
28/11/2016

2. RADIATION DAMAGE STUDIES IN SILICON SENSORS(EP-DT-DD)
Outline
RADIATION DAMAGE STUDIES IN SILICON SENSORS(EP-DT-DD)
Activities in the Solid State Detectors (SSD) team
Cryostat upgrade
Research projects
Activities in the Irradiation Facilities (IRRAD) team
RADMON portable readout system
NIEL calibration
Future work

3. ACTIVITIES in the SSD team

4. Cryostat upgrade - Overview
Closed-cycle helium cooling machine.
Purpose: characterization of radiation induced defects on silicon
From 20K to room temperature with a controlled heating rate (11K/min)
Error in the temperature measurement & slow response
PCB substrate non conductive
Heat flow through cables
𝐼𝐿(𝑇)∝ 1 𝑇 2 𝑒 − 𝐸 𝑔 2 𝑘 𝐵 𝑇
CONCLUSION: RE-DESIGN OF THE SAMPLEHOLDER FROM SCRATCH
(Since april: design & prototype work)
Sensor colder than DUT when warming up
~6K

5. Connexion to PCB using spring loaded contacts
Cryostat upgrade – New concept
New design aims for:
Low mass – Fast response to ∆T
High thermal conductivity of PCB
Low thermal leakage through cabling
Plug & play
Challenge: PCB compatible with the rest of setups in the laboratory!
Minimize copper mass
PCB
Alumina substrate
Detector
Reduced PCB size (no SMA connectors)
Support frame
Pressing mechanism
Sample-holder
Connexion to PCB using spring loaded contacts
Stainless steel micro-coax to cryostat flange
Cryostat tip

6. Preliminary design To be refined (support by EP-DT-CO)
Cryostat upgrade – List of tasks
Design & production of ceramic PCB prototype 
Signal integrity test w. picosecond laser illumination 
Test in cryocooler (proof of concept) 
PT1000 calibration down to 10K 
Do we really need the temperature reference sensor?
Final PCB & mechanical design 
Preliminary design To be refined (support by EP-DT-CO)
~2K

7. Research projects & other tasks
New project: study of defects in very thin silicon sensors (down to 50um thickness, different types, resistivity…)
Characterization before and after irradiation
Use of the Cryostat for defect characterization
Study of charge detrapping times at low T, using CW (LED) illumination
Setup upgrade: CV-IV measurements in cold chamber
Replication of an existing setup
Some Labview code adaptation needed

8. ACTIVITIES in the IRRAD team

9. RADMON project – Overview
Development of dosimeters (PIN diodes and RadFETs) for monitoring dose and fluence.
Many RADMON boards installed in the LHC experiments
Readout integrated in the detector control system
My task:
to develop a portable readout system for “small installations”
Project on the side, ongoing since many years
Last meeting:
Full characterization of the system DC-DC converter
Conclusion: it can be used if some readout timing constraints are relaxed

10. RADMON project – Recent evolution
Added some additional circuitry to protect the dosimeters when switching from one to the other
First implementation of the readout protocol
Very basic: infinite loop with the readout of a full RADMON board
Measurements sent to database
Online data visualization
First “functional” prototype installed in IRRAD
Very helpful for debugging (HW & SW)
Finally, quite steady data acquisition.

11. RADMON project – Current work
Work on the software part to have a stable system with a webDAQ
Web DAQ HTML
Assign profile to dosimeter
Activate/desactivate dosimeter …
Create readout profile
Linino
Profiles.php
ConfigReadout.php
Radmon-daemon.php
Arduino sketch
Wait for instructions
Readout dosimeter
Send to DB
VisuData.php
profile1.txt
profileN.txt
SQL database
SD card

12. NIEL calibration T = 20oC After 80 min. @60oC к = 0.58
Non ionizing energy loss (NIEL) hypothesis: displacement damage effects scale linearly with the amount of energy imparted in displacing collisions.
We study how the leakage current scales with fluence, for comparison with other irradiation facilities (different particles, energies)
Irradiation of different sets of diodes at several fluences for this study  Data analysis still on-going
T = 20oC
After 80
к = 0.58

13. Conclusions Solid State Detectors (SSD) team
Ceramic PCB prototype produced and tested
Proof of concept of the new sample-holder concept in the cryostat
Next…
Enter the final design phase of the sample-holder
Operation of the setup for the different research projects on-going (thin sensors, LED illumination, etc)
Data analysis software
Irradiation facilities (IRRAD) team
RADMON portable readout system prototype installed and tested in IRRAD
Develop a second prototype version of the RADMON readout to test in the next irradiation campaign (Spring 2017)
Installation of the current prototype in GIF++ during winter break
Analysis of RADMON data in the LHC