1. NA61 PSD.
Upgrade status.
Institute for Nuclear Research RAS, Moscow

2. NA61 PSD is now fully quipped with new electronics
- tested on temperature regulation and control stability – OK
- tested on data acquisition readout - OK
24 June 2014 2

3. New cooling system, FEE, HV and control system for one module
Electronics of one PSD module
after upgrade
Readout module
(old one)
New electronics 3

4. Schematic view of slow control and temperature control readout system for NA61 PSD
HVSys, Dubna
flat cable HV
control
box
HVSys
HVSys
HVSys
. . .
HVSys
LAN
TEC
TEC
TEC
TEC
RS485 network (twisted pair)
USB
USB to RS485
Converter
PSD readout PC
USB to RS485
Converter
(We will have 2 RS485 networks X 22 channels each)
The system has been tested for stability - OK
24 June 2014 4

5. First tests of DAQ have shown large noise levels..
one event
pedestal
spectrum
MIP is here
- the source is: DAQ concentrator boards
- the reason: no common ground after
change to new HV power
scheme
- to fix: make common ground between
new and old electronic modules.
24 June 2014 5

6. But.. we have another noise source: TEC-1091 controller.
TEC OFF
TEC ON
effect on pedestal
one event
one event
TEC OFF
TEC ON
effect on MIP-like signal
one event
one event
24 June 2014 6

7. TEC-1091 effect on pedestal and MIP-like signal
TEC OFF
pedestal
MIP-like
TEC ON
Why do we not see a significant effect? The answer is: just by chance:
signal calculation
pedestal calculation
~110 “ticks”
100 “ticks”
24 June 2014 7

8. Possible solution to avoid noise from TEC-1091 controller:
cover TEC PCB with shield (we have used a copper foil)
TEC OFF
pedestal spectra
TEC ON
one event
one event
TEC ON + shield on TEC
TEC OFF
TEC ON
TEC ON + Shield
one event
24 June 2014 8

9. Another possible solution to avoid noise from TEC-1091 controller:
use sine fit to calculate pedestal level:
- disadvantage: too slow (only for
offline analysis)
pedestal spectra
MIP-like spectra
0-19 ch pedestal
sine fit pedestal
0-19 ch pedestal
sine fit pedestal
24 June 2014 9

10. Cooling system test results (48 hours)
Room temperature
Temperature in one module at different times
New MAPDs cooling system based on the Peltier elements
provide stable given temperature in each module
Temperature of all 44 modules at given time 10

11. 1) the new electronics has been mounted and tested:
Conclusions:
1) the new electronics has been mounted and tested:
- noise from concentrator boards have been eliminated with common ground
- TEC-1091 controller noise has been studied:
a) period of noise signal = range of pedestal ↔ signal => minimum noise effect
b) offline sine fit for pedestal => minimum noise effect
MIP-like signal is visible in (a) and (b) as well
2) slow control and temperature control systems have been tested and show no problems
24 June 2014 11