1. CMS-ECAL Front-End monitoring Matteo Marone
On behalf of CMS-ECAL group

2. Outline ECAL Detector Control Unit (DCU) Online Readout Chain
Integration with Conditions DB and Detector Control System
Thermal Stability Analysis
2/22

3. CMS/ECAL at LHC 36 Supermodules, 1700 Crystal each
Barrel crystals
Pb/Si
Preshower
Barrel
Supermodule
36 Supermodules, 1700 Crystal each
4 Endcap Dees, 3662 Crystals each
8 meters long
90 Tons of Crystal
More than channels
Barrel crystals
Endcap
Barrel
Supermodule
3/22

4. ECAL Requirements ECAL response sensitive to variations of:
DCU
Online Chain
CondDB & PVSS
Thermal Stability
ECAL response sensitive to variations of:
Crystal transparency (irradiation)
Temperature: ∂(LY)/∂T ~ -2%/oK
1/M(∂M/∂T) ~ -2%/oK
High voltage: 1/M(∂M/∂V) ~ 3%/V
affect the resolution constant term
Temperature 0.1oC level
HV stability at the 10 mV level
M= Photodetector
gain
LY= Light Yeld
4/22

5. Detector Control Unit (DCU)
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
special ASIC used to monitor
Front End electronics parameters:
Currents
Temperatures
Voltages
Quantities measured with 12 bit ADC
Sensitivity:
Temperature
0.012 °C
Currents
340 nA
Voltages
~ mV
5/22

6. On Detector electronics
LVR MB
VFE FE
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
1 DCU every VFE card
Basic Read-out Geometry:
5X5 crystals (TT)
8 DCUs per TT ~ 20000
Leakage current
Crystal temperature
Voltage Supplies
Temperature &&
Voltages
Trigger
Light
Current
APD
Crystal
Energy
Voltage
Bit
MGPA
ADC
VFE FE
DAQ
Optical Fiber
DCU
DCU
DCU MB
6/22

7. DCU Software Architecture
XDAQ
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
DCU Supervisor
DATA
CondDB
DCU Reader
Calibrations
DCS – Detector Control System
Soap PC
Storage
Data
Files
Converter
Write
CondDB
8/22

8. PVSS DCU Project DEAMON
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
DEAMON
DCU final readout sequence foresees to send DCU data:
Changing values ~ 5 min
Whole ECAL ~ 20 min
9/22

9. Conditions Database
The entire amount of data has been stored into the DB (so far)
Data easily browsable through WEB
10/22

10. Precision Temperature Monitoring (PTM)
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
• PTM data Measurements: 10 PTMs/SM (water IN, water OUT, 4 on grid, 4 on thermal screen)
Full autonomy of the system in every aspect and functionality
Independent and reliable temperature monitoring of ECAL FE electronics
11/22

11. Thermal Stability DCU measurements have been used for :
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
DCU measurements have been used for :
- validating the detector thermal stability during operational periods
- investigating sources of problems/dead channels
50 DCU RUNS
DURING CRAFT
CALIBRATE
DCU RAW DATA
(ADC PEDESTAL)
INDEPENDENT
TEMPERATURE
MEASUREMENT
TEMPERATURE
CONTROLLED
ENVIRONMENT
12/22

12. Calibrations from Cosmic Stand
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
Calibration with PTM in the Cosmic Stand
EB-1
after
before
13/22

13. Analysis Strategy 50 DCU runs taken
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
50 DCU runs taken
Calibration constants have been applied
Temperature homogeneity and stability have been checked using DCU and PTM data
PTMs also measure the cooling stability
Some constants did not correct properly
Replaced VFE
EB-16
Isolated Channel
New Constants
Using P5 data
New calibrations only when needed
14/22

14. Results(1):Barrel Temperatures
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
These data refer to a 4 weeks periods of global run
41 Missing measurements (32 recoverable) – Black Spots
33 Thermistors out of range (under investigation): White spots
15/22

15. Results(3):Temperature
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
ECAL=(18.12±0.04) oC
PTM=(18.10±0.02) oC
Good temperature homogeneity:
RMS ~ 0.04 oC
Blue area corresponds to sensors
close to the highest density of LV cables
PTM system: average temperature is 18.1 ± 0.02 °C, in very good agreement with the one measured by the DCU system.
16/22

16. Results(2):Temperature Vs time
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
DCU measurements (in black) compared with an independent temperature measurement provided by a set of devices (PTM) M4 M1
Water IN
PTM and DCU well correlated
17/22

17. Barrel Stability
ECAL
DCU
Online Chain
CondDB & PVSS
Thermal Stability
Distribution of temperatures RMSs for each of the ECAL Barrel thermistors during CRaFT (logaritmic scale).
Peak average RMS is ± °C. 98% of channels have RMS<0.1 °C.
Values in the right-end side tail are channels affected by some read-out problems.
18/22

18. Endcap Temperatures
Few missing thermistors (no read-out, mostly recoverable)
No DCU chip calibrations -> Big temperature spread
One thermistor every SuperCrystal (SC)
Border are partial SC (3X5,2X5,1X5) recomposed into SC (not yet read)
19/22

19. Endcap: PTM Vs Time
20/22

20. Endcap Stability DCU (Not RMS Calibrated) spread PTM
Both DCU and PTM measurements
signal less stability in EE
EE during CRaFT was still under
commissioning
21/22

21. monitoring of the calorimeter during
Conclusions
DCU read-out commissioned both for ECAL Barrel and Endcaps
DCU integration in the framework has been successfully done
Data communication with CondDB and PVSS achieved
Validation of detector thermal stability and bad channels investigation have been carrying out
DCU will help to ensure
monitoring of the calorimeter during
the LHC run
22/22

22. Spares

23. What is monitored in detail
APD:
currents (1 DCU for xtal = 1700/SM)‏
t3mperatures (1 DCU every 10 xtals = 170 values/SM):
VFE & LVR:
DCU internal temperatures (8x68 values /SM)‏
MEM box:
VDD_1, VDD_2, 2.5 V, Vinj (4X2 values / SM)‏
DCU internal temperatures (1x2 values /SM)‏
LVR:
3 thermistors
2.5 V (12x68 values / SM)‏
4.3 V (2X68 values / SM)‏
0.1 V – inhibit (1X68 values /SM)

24. XDAQ
CMS online software framework in which all the online applications are implemented (C++):
Used for configuration, messaging, event handling
Extensive use of XML
Scalable: from small test stand to the CMS DAQ
XDAQ user application is a collection of
call-back functions, typically attached with FSM transitions
SOAP messages drive application's call-back
7/17

25. DCU to DCS (Detector Control System)
DCUSupervisor performs the read-out, builds the PVSS datapoints and sends them to DCS using the PSX interface
DCS provides:
early detection of abnormal conditions (issuing appropriate warnings and alarms)
hard-wired interlocks
All ECAL DCS applications have been developed using the commercial ETM SCADA (Supervisory Control And Data Acquisition) software PVSS 3.6 and standard Joint Control Project (JCOP) framework components
PSX
Server
DCU Online
software
SOAP
WRITE DPs
DCU PVSS Project
Linux
Windows
9/17

26. ECAL Run Control Web Interface
DCU runs are currently taken using the ECAL Run Control whenever needed/possible
A tree of finite state machines controls the data taking operation of the experiment (Function Manager)
It has been used successfully during the global run
12/17