1. PARISROC Photomultiplier Array Integrated in SiGe Read Out Chip
Selma CONFORTI DI LORENZO
Journées Jeunes Chercheurs 2010

2. Journées Jeunes Chercheurs 2010
Outline
PMm² R&D program
PARISROC ASIC*
(*Application Specific Integrated Circuit)
Measurements
PARISROC second version
Journées Jeunes Chercheurs 2010

3. Motivations for PMm² project (1/2)
Large underground detectors
Megaton Mass Physics
proton decay
solar neutrinos
atmospheric neutrinos
neutrinos from supernova νµ
11146
20-inch
1885
8-inch
The neutrinos non-charged particles
low interactions with the matter
The principle of their detection: neutrinos interacts
with the matter producing charged particles that can create Cerenkov light
SuperKamiokande
Kamioka Observatory Japan
1000 m rock/50 kt
11, inch PMTs;
Each PMT is connected to high voltage supplies
and signal processing electronics via a single cable
Information from the PMTs:
The energy, direction,
interaction point
and
the type of the charged particle
10 p.e./ MeV
Journées Jeunes Chercheurs 2010

4. Motivations for PMm² project (2/2) Journées Jeunes Chercheurs 2010
Hyper-Kamiokande
JAPAN
MEMPHYS (Megaton Mass Physics detector)
EUROPE
Photo-detection
inch PMTs
Detector design
3 shafts 440 kt
Photo-detection
inch PMTs
Detector design
2 twin tunnels 2*275kt
LBNE (Long Base line Neutrinos Experiment)
USA
Extension of mass to 500 kt
Larger number of PMTs
(Factor 10)
Photo-detection
~ inch PMTs
Complexity reduction
Journées Jeunes Chercheurs 2010

5. PMm² general description
Replace large PMTs (20-inch) by macro pixel (2*2 m²) of 16 smaller ones (12-inch)
with central ASIC :
- Triggerless front-end electronics with independent channels;
- Charge and time measurement;
- Common High Voltage;
- Only one wire out (DATA + power supply) to the surface DAQ (DATA ACQUISITION).
Front-end electronic
closed to the PMTs array
underwater =
PMm² stands for
“Square Meter Photomultiplier”
Journées Jeunes Chercheurs 2010

6. Journées Jeunes Chercheurs 2010
PMm² ANR ( ) (1/2)
«Electronique innovante pour photodétecteurs distribués en physique des particules et astroparticules»
Journées Jeunes Chercheurs 2010

7. Thesis objective ASIC realization Second phase First phase
Meglio un giorno da Fisico
che 100 da Ingegnere
ASIC realization
Second phase
Architecture conception
First phase
Study of ASIC requirements
CADENCE: “Composer schematic editor”→ schematic design
“ Spectre” → Simulations
Third phase
Design and realization
Fourth phase
Prototype measurements
CADENCE: “Virtuoso”→ Layout
“ Assura” → Layout verification
Journées Jeunes Chercheurs 2010

8. Journées Jeunes Chercheurs 2010
ASIC requirements
- SoC (System on Chip);
- Analog F.E. + charge and time digitization;
- 16 PMTs independent channels;
- 1/3 p.e. 100% trigger efficiency;
- Charge dynamic range 0 to 300p.e. (at PMT gain 106);
- 1 ns time stamping resolution;
- Each channel has a variable gain:
To compensate gain vs HV spread for the 16 PMTs;
- Triggerless mode:
All the PMTs signals above the threshold (1/3 p.e.)
generate a trigger and are converted in digital data.
Journées Jeunes Chercheurs 2010

9. PARISROC 1 Architecture Journées Jeunes Chercheurs 2010
15ns
5ns
Input: 1pe; G_pa=8
20mV/div
50ns/div
Journées Jeunes Chercheurs 2010

10. Journées Jeunes Chercheurs 2010
PARISROC 1 Schematic
Journées Jeunes Chercheurs 2010

11. Journées Jeunes Chercheurs 2010
PARISROC 1 Simulation
To model PMT
input signal
Output signals
Linearity
Noise
Journées Jeunes Chercheurs 2010

12. Journées Jeunes Chercheurs 2010
PARISROC 1 Prototype
Sent for fabrication in June 2008 to AMS foundry received in December 2008
Technology: AMS SiGe 0.35 µm
Surface: 17 mm²
Journées Jeunes Chercheurs 2010

13. PARISROC 1 Measurements (1/2) Journées Jeunes Chercheurs 2010
“Test group”
Oscilloscope
Signal Generator
TEST BENCH
TEST BOARD
DC supply
Dedicated
Labview
Input signal
short for
Laboratory Virtual Instrumentation Engineering Workbench
50 fC and 50 pC
(from 1/3 to 300 p.e.) at PMT gain 106
Journées Jeunes Chercheurs 2010

14. PARISROC 1 Measurements (2/2) Journées Jeunes Chercheurs 2010
Each analog block tested
in terms of:
Output signals
Linearity
Noise
Triggerless mode → S-Curve
1/3 p.e. 100% trigger efficiency → Trigger efficiency
Charge and time digitization → Complete chain
Journées Jeunes Chercheurs 2010

15. Journées Jeunes Chercheurs 2010
S-Curve
When the signal is lower than the threshold
the trigger efficiency is of 100%,
when the signal amplitude becomes higher than the threshold,
the trigger efficiency falls progressively to zero.
Output Trigger No
Output Trigger
Journées Jeunes Chercheurs 2010

16. Trigger efficiency (1/2) Journées Jeunes Chercheurs 2010
Channel one scanning
the threshold
and
the charge until 3 p.e.
3 p.e.
0 p.e.
Journées Jeunes Chercheurs 2010

17. Trigger efficiency (2/2) Journées Jeunes Chercheurs 2010
The linearity is correct down to 100 fC which corresponds to 10 σ (σ =13 fC) noise
instead of the 5 σ noise expected from theory
Coupling signal
5 σ noise > 1/3 p.e.
Minimum
threshold
Clock noise
Minimum
threshold
LSB DAC= 1.7 mV
Journées Jeunes Chercheurs 2010

18. Overall chain measurements
The whole chain is, now, tested injecting a charge in the input of the channel:
the signal is amplified, auto-triggered, held in the SCA cell and converted by the ADC.
Clock
Noise
Residuals
-6 to 14 UADC
Charge distribution for channel one
and 3 p.e. of injected charge
Until 50 p.e.
A nice linearity of 1.5%
and
a noise of 6 UADC are obtained (~ 6 mV)
10 bit ADC
Gpa 14
SSH 50ns
LSB 1 mV
28000 events
mean value plotted
Journées Jeunes Chercheurs 2010

19. Journées Jeunes Chercheurs 2010
Fine Time
tested by IPNO team
The TDC has been reconstructed from the time values saved in the analog memory and converted by the ADC (10-bit).
Dynamic range of the two ramps 622 UADC → 83 ns
with a resolution of 133 ps/ch.
“Blind zone” of around 30 ns
thus the 30%
offset in the start
and in the end of the ramps
error in time
of 6 ns
linear zone of 70 ns
Ramp 1
Ramp 2 C1 C2
Residuals (UADC)
- 6 to 6.5
- 6 to 7.5
- 6 to 8.3
- 6 to 9
Time error (ps)
785
918
1.1 1
Journées Jeunes Chercheurs 2010

20. Journées Jeunes Chercheurs 2010
16 one-inch PMTs (1/2)
tested by IPNO team
The 16 PMTs tests:
PARISROC chip,
the PMm2 box (all in the pressure vessel)
the DAQ software.
Journées Jeunes Chercheurs 2010

21. Signal acquired remotely Journées Jeunes Chercheurs 2010
16 one-inch PMTs (2/2)
tested by IPNO team
Remote Capture of PMT Charge Spectrum from PMm2 full electronics (on Air)
Signal acquired remotely
(250 km in this case)
via TCP/IP network
Single p.e. response
for each 16 channels
after
pedestal subtraction
and
gain matching.
Threshold
0.2 p.e.
Journées Jeunes Chercheurs 2010

22. Measurements conclusions Journées Jeunes Chercheurs 2010
Good PARISROC 1 overall performances:
Triggerless mode→ OK
Charge and Time digitized data → OK
Some limitations:
A clock coupling noise
An extra source of noise
A discriminator coupling signal that limits the minimum threshold at around ½ p.e.
TDC blind zone
Journées Jeunes Chercheurs 2010

23. Why a new version of PARISROC ?
Designed to solve some minor bugs of v1 (extra noise, fine time)
To reduce loss of events
PARISROC 1:
- PMTs 5kHz
- Conversion 12 bits
- Read out 10 MHz
- Analog memory depth 2
loss of events of 16 %
Noise rate
Number of
SCA capacitances
ADC bits
readout frequency
Lost events (%)
5 kHz 2 12
10 MHz
16  12
0.1 kHz
0.008  0.6 10
6  10 4
3  6
20 MHz
1  4
40 MHz
0.3  2.0
0.3  2.2
0.007  0.5 8
0.24  3.1 9
0.007  0.7
PARISROC 2:
- PMTs 5kHz
- Conversion 8 bits
- Read out 40 MHz
- Analog memory depth 2
loss of events of 0.3 %
Spead-up the trigger processing !!!
Decreasing the ADC bits and increasing the readout frequency
Journées Jeunes Chercheurs 2010

24. PARISROC second prototype (1/2) Journées Jeunes Chercheurs 2010
2nd version submitted in November 2009 and received in February 2010
Conceived to solve some minor bugs of v1 (extra noise)
Improvements:
- ADC resolution decreased from 12 to 10 bits;
- Keep the dynamic range precision using 2 gains;
- Improvement to coarse and fine time;
- Increase clock to 40MHz.
Technology: AMS SiGe 0.35 µm
Surface: 17 mm²
Package: CQFP160
Journées Jeunes Chercheurs 2010

25. PARISROC second prototype (2/2) Journées Jeunes Chercheurs 2010
Test started in March 2010
- Improvement in noise : low noise; no clock noise
- No coupling signal;
- Trigger 1/3 of p.e. PMT gain 106)
(limited in the first version at around ½ pe)
Good linearity down to 35 fC= 5 σ noise
σ= 7 fC
coupling signal
improved
threshold
can be set at 1/3 of p.e.
5σ noise < 1/3 p.e.
clock noise
improved
Journées Jeunes Chercheurs 2010

26. CONCLUSIONS Project requirements PARISROC 1 PARISROC 2
Triggerless acquisition OK
Dynamic range 0 to 300 p.e.
(at PMT gain 106)
(up to 500 p.e.)
(up to 600 p.e.)
Time stamping
with 1 ns of time resolution X
(Blind zones)
1/3 p.e. 100% trigger efficiency
(1 p.e.)
Minimum input rate 5 kHz
(loss events 16%)
(loss events 0.3%)
The PARISROC2 ASIC fulfils the requirements of the project.
It is available to be used in physics experiments and tested in real detectors.
Journées Jeunes Chercheurs 2010

27. Journées Jeunes Chercheurs 2010
Perspectives
The idea of the PMm² project to perform a new generation of “smart photo-detectors”
composed by sensor and readout electronics has been demonstrated
Demonstrator realized by the IPNO with 16 x 8-inch Hamamatsu tubes.
Future test will be performed with this demonstrator and the
PARISROC 2 ASIC and it might be used by
MEMPHYNO collaboration (APC and LAPP).
Different international experiments are interested by the ASIC as:
Chinese project LHAASO
The European MEMPHYS or LENA
LBNE in USA.
Journées Jeunes Chercheurs 2010

28. Journées Jeunes Chercheurs 2010
J'ai soutenu le 6 octobre!!!!!
Selma Simpson
Merci!!!!
Journées Jeunes Chercheurs 2010

29. Journées Jeunes Chercheurs 2010
Backup
Journées Jeunes Chercheurs 2010

30. A Large High Altitude Air Shower Observatory LHAASO Project
Tibet Site in Yangbajing Valley
Gamma ray astronomy from 40GeV to 1PeV;
Cosmic ray physics from 10TeV to 1EeV.
4360 m
YBJ, Tibet
4300m a.s.l.
Journées Jeunes Chercheurs 2010

31. A Complex Detector Array
LHAASO Project
A Complex Detector Array
Scintillation detector
And
muon detectors
Scintillation detector
Array
Cerenkov Telescope
Array
Water Cerenkov
Detector
Journées Jeunes Chercheurs 2010

32. MEMPHYNO Project A small-scale MEMPHYS prototype Test bench for
photo-detection and electronic solution
for LARGE detectors
Full test of the “electronic and acquisition” chain;
Trigger threshold study;
Self-triggered mode;
Track reconstruction performances.
* Michela Marafini “Water cerenkov R&D in Europe” NNN09
Journées Jeunes Chercheurs 2010

33. Journées Jeunes Chercheurs 2010
Digital part
4 modules: Acquisition, Conversion, Read Out and
Top manager.
Acquisition: Analog memory
Conversion: Analog charge and time into 12 bits digital value saved in register (RAM)
Read Out: RAM read out to an external system
Selective Read Out
Only hit channels are readout
Readout clock : 10 MHz
Max Readout time (16 ch hit) : 100 µs
52 bits of data / hit channel
Readout format (MSB first) : 4 bits channel # + 24 bits timestamp +
12 bits charge + 12 bits time
Journées Jeunes Chercheurs 2010