Status and plans of PSD test run in
October - November 2015
F.Guber, M.Golubeva, A.Ivashkin, S.Morozov, O.Petukhov
INR, Moscow,
MEPHI, Moscow
- Short summary of the PSD problems in Ar-run;
- PSD upgrade for proton and Pb runs in Nov. 2015;
a) New short small module in front of PSD;
b) New fast photodiodes in short and central module;
c) Modification of analog electronics in short and central module;
- Beam tests:
-
a) recalibration of modules at different temperatures;
b) study of response short and central module;
c) study of one of large module response with of CAEN DT5742 readout;
d) study of one of large module response with PADIWA FEE and TRB3 readout
Role of the PSD in NA61
NA61
- Measurement of centrality: b~ A - Nspect
(selection of centrality at trigger level)
- Measurement of event-by-event
fluctuations
- Reconstruction of the reaction plane
-high granularity:
transverse homogeneity of energy resolution,
reaction plane measurements ?
-compensated calorimeter (e/h = 1), lead/scintillator sampling ratio 4:1
high energy resolution <70%/sqrt(E)
- longitudinal segmentation (10 sections per module)
PID, background rejection, improvement of energy resolution
light readout from each sections by novel MAPDs
to provide large dynamic range,
to exclude nuclear counting effect
2
120 cm
Main features of the PSD
120 cm
44 modules:
16 central (small),
28 outer (large) modules.
Short summary of the PSD problems in Ar-run
• Shower leakage from heavy fragments at rear side of the PSD (~12% lost in the
PSD energy deposition at E beam = 150 AGeV),
• MAPD pixel saturation (additional 9% lost in the PSD energy deposition
at ~100K S1/spill),
• Limited dynamic range of ADC - saturation at 1V (corresponds to ~10
nucleons/module),
• Saturation of trigger signal (adder) at 2.5V ( corresponds to ~25
nucleons/module),
Last two problems were solved for Ar-beam by directing the beam in the PSD
center. In this case the shower is distributed over 4 central modules.
The problem with shower leakage from heavy fragments was partially solved by
adding short (~0.5 int. length) beam degrader in front of PSD.
3
How to solve these problems in future 132Xe and 208Pb runs
• Beam must hit the PSD center (cross of 4 central modules). Additional 2
section short module will be installed on beam axis in front of the PSD.
• For Xe beam with energy from 13 GeV to 40 GeV the energy deposition would
be less than for Ar beam energy at 150 GeV.
• For Xe beam with energy from 70-150 GeV the amplifier gains in four central
modules should be reduced 4 times.
• The trigger signal from other central modules should be attenuated 4 times to
keep the equivalence of energy in trigger.
• The trigger signal will be saturated in this case at 100 nucleons/module or 400
nucleons/(4 modules).
• In this case, dynamical range of ADCs in 4 central modules will be extended to
40 nucleons/module or 160 nucleons/(4 modules)
(OK for 132Xe, but not for 208Pb ).
4
Proposed PSD upgrade for proton and Pb test runs
in October and November 2015
•
To minimize the risk of the PSD operation in the proton and Pb runs a
limited action is proposed for the PSD upgrade in 2015:
• Construction of short 2 sections module with 12 Pb/Scint sandwiches (~1.1
λint) and WLS-fiber readout. It would be installed in front of module #6 (to
reduce the shower leakage.) .
• New FEE board with fast MPPCs and amplifiers with reduced gain will be used
here.
• The same board with fast MPPCs and low gain amplifiers will be used in
module #6.
• The readout electronics would be the same.
In this geometry the module #6 would have an limited ability to detect a single
nucleon, while a good hadron shower confinement for beam ions.
5
Installation of short module
in front of module #6
•
Installation of additional ~1.1L0
active degrader (2 sections) in
front of module #6.
•
It includes 12 Lead/Scintillator
sandwiches with WLS-fiber light
readout.
•
12 WSL-fiber pass to PSD
horizontal support platform and
collected into 2 optical
connectors.
•
2 optical connectors are viewed
by 2 fast MPPCs with the
corresponding FEE.
6
Present status of the short module and electronics construction
Assembling of short module at
workshop. All components are ready
and available. Final assembly and
installation is ongoing at CERN during
20 -30 September 2015.
New boards with MPPCs and amplifiers
are ready.
Work plan and tests at nearest proton run:
• Recalibration of PSD modules with muon beam at different MAPD
temperatures (20 0C, 23 0C);
• Energy scan of a few modules in the range 20-160 GeV;
• Installation of new short module in front of module #6;
• Installation of new FEE with new FEE and fast MPPCs in module #6;
• Calibration of new short module at muon and proton beam;
• Muon calibration of module #6 with new FEE and fast MPPCs;
• Energy scan of module #6 with new FEE and fast MPPCs;
• Additional tests (see next slides).
Additional tests:
• Study of the PSD response with present FEE, present MAPDs, but
with CAEN DT5742 (based on DRS4) readout electronics in one
large module for muon, proton and Pb beams;
•
Study of the PSD response with present MAPDs, but using
prototype of PaDiWa3 AMPS FEE boards and TRB3 readout
electronics in one large module for muon, proton and Pb beams
(MoU between NA61/CBM collaborations).
Beam test of the PSD module readout by use of 16 channels
CAEN DT5742 (based on DRS4 chip)
The goal of beam test – study PSD response between 20 and
150 GeV/c proton energy and Pb beam (30 AGeV) with PSD
amplifiers with high and low gains, study noises, calibration at
muon beam. Influence of TEC pick-up noises.
16+1 channel 12 bit 5 GS/s
Switched Capacitor Digitizer
based on DRS4
Beam test of the PSD module with PaDiWa FEE
and TRB3 readout (MoU between NA61/CBM collaborations)
The goal of test – study PSD module response with full readout chain of the CBM
PSD (PaDiWa3 AMPS FEE +TRB3) between 20 and 150 GeV/c proton energy and
Pb beam (30 AGeV) Get first results with these electronics. Will be very useful
for further development for the PSD CBM.
PaDiWa3 AMPS FEE boards
(8 channels).
We have 2 boards.
The TRBv3 is a multi purpose time digitisation
board with high resolution (23 ps RMS) Timeto-Digital Converters (TDC) realized in FPGAs
(Lattice ECP3-150EA). The board can handle
up to 256 channels and is equipped with a
DAQ functionality, with fast data transfer via
gigabit Ethernet.
The PSD lead test beam schedule (Nov 2015)
The schedule will be prepared after Oct. test run.
Next stage of PSD upgrade in the beginning of 2016.
• Next stage of PSD upgrade is the modification of the rest of 3 central
modules around the PSD center: replacement of MAPDs, new
amplifiers with reduced gain and new calibration with muons.
• It would be done if the modification of module #6 will be successful.
In case of any problem with new photodetectors a previous
electronics with old MAPDs would be returned.
• After modification of all 4 central modules the beam would hit again
the PSD center (the corner of 4 modules).
• Such configuration extends the dynamic range by factor 4
additionally. That might be important for Pb-beam at 150 GeV.
• The decision on upgrade of the rest 3 central modules would be done
after 2015 Pb test run.
• New PSD beam tests are requited in 2016.
13
Thank you
DRS4 readout electronics extend the PSD heavy ion
detection possibility
Future variant :
MAPD
or/and
Low
gain
output
G=30
High gain
output
G=30x4
DRS
(for high energy deposition)
DRS
(for low energy deposition
+ muon calibration)
- Much larger dynamic range for ADCs (two ADCs for low/high gain
amplifiers in each section).
- Muon calibration and detection of heavy fragments would be done
in different ADCs.
- No TEC pick-up noises because the signal after amplifier is not
attenuated as now and is much higher than noise amplitude.
Status of tests of 16 channels CAEN DT5742 at INR
- All electronics, cables, connectors are available.
- DAQ in standalone mode is prepared and tested.
Photo of test bench with CAEN DT5742
at INR,Moscow
Some test results of linearity response
by using LED.
Status of PaDiWa FEE and TRB3
readout tests at INR
- All electronics, cables, connectors are available.
- DAQ in standalone mode is prepared and tested.
Photo of test bench with
PaDiWa3 AMPS FEE +TRB3
at INR, Moscow
Some test results obtained in Moscow
The test results will be very important for the CBM PSD
and for MPD at NICA.