1. RPC – status / results Blanco On behalf of HADES RPC Group
GSI
D. Gonzalez
W. Koenig
LIP
A. Blanco N. Carolino O. Cunha
P. Fonte
L. Lopes
A. Mangiarotti A. Pereira C. Silva
C.C. Sousa
USC
D. Belver
P. Cabanelas
E. Castro J.A. Garzón G. Kornakov
M. Zapata
IFIC-Valencia
J. Diaz
A. Gil
In this presentation: hardware notation
S1, S2, S3 ,S4, S5, S6

2. Outlook . . Hardware status Integration status
Outlook
Hardware status
Integration status
Intrinsic RPC performance
Calibration status

3. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Run for the entire beam time without major problems
In S4 all channels in the high polar angle (row >~ 22) in the front part show an strange behavior. They count less in the right side. Most probably correlated with a problem in the low voltage PS (more in next slides).

4. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Strange behavior. Count less in the right side. May be correlated with LV PS. S4

5. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Run for the entire beam time without major problems
In S4 all channels in the high polar angle (row >~ 22) in the front part show an strange behavior. They count less in the right side. Most probably correlated with a problem in the low voltage PS (more in next slides).
Some FEE problems spread over all sectors.
Charge measurement is not working in one side (still useful cell). Solvable, replace FEE S1-FR4-R, S3-FC19-R, S3-FC28-R, S4-BC5-R, S4-FR21-R, S4-BR4-R

6. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Run for the entire beam time without major problems
In S4 all channels in the high polar angle (row >~ 22) in the front part show an strange behavior. They count less in the right side. Most probably correlated with a problem in the low voltage PS (more in next slides).
Some FEE problems spread over all sectors.
Charge measurement is not working in one side (still useful cell). Solvable, replace FEE S1-FR4-R, S3-FC19-R, S3-FC28-R, S4-BC5-R, S4-FR21-R, S4-BR4-R
Dead channels. Only solvable with a major intervention. Not foreseen.
S4-BL1 disconnected on purpose due to high percentage of streamers.
S6-BR5-R disconnected during transport from Coimbra. Still useful for trigger.

7. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Run for the entire beam time without major problems
In S4 all channels in the high polar angle (row >~ 22) in the front part show an strange behavior. They count less in the right side. Most probably correlated with a problem in the low voltage PS (more in next slides).
Some FEE problems spread over all sectors.
Charge measurement is not working in one side (still useful cell). Solvable, replace FEE S1-FR4-R, S3-FC19-R, S3-FC28-R, S4-BC5-R, S4-FR21-R, S4-BR4-R
Dead channels. Only solvable with a major intervention. Not foreseen.
S4-BL1 disconnected on purpose due to high percentage of streamers.
S6-BR5-R disconnected during transport from Coimbra. Still useful for trigger.
Problems with trigger signal in some MBs, which in some sectors is not counting correctly for M1 multiplicity, not affecting high multiplicity triggers. To be check. Solvable, replace MB when necessary.

8. Hardware status on Aug11 and today
Hardware status on Aug11 and today
M1 multiplicity, S2
Present in S1 & S2 FL BL FC BC FR BR
Rate (Hz/cm2)
Second MB in back layer
ROW

9. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Low Voltage PS S4 & S2 should be replaced, hardware failure. This happened after beam Time. Although also happened before. To be studied. Solvable, replace PS.

10. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Anomalous increase of Current & Voltage drop => Permanent failure of LV PS S2, S4. To be understood
Voltage
Current

11. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Gas leaks
Input
Output
Diference
Flow (cc/min)
Time (h)

12. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Gas leaks
Input
Output
Diference
Before After
Flow (cc/min)
S4 leak reparation
Time (h)

13. Hardware status on Aug11 and today
Hardware status on Aug11 and today
Gas leaks
Input
Output
Diference
S1 & S5 leak ~7 cc/min
Flow (cc/min)
Time (h)

14. Hardware status on Aug11 and today
Hardware status on Aug11 and today
All these problems will be checked and repaired in January 2012

15. Integration status . . Basically finished
Integration status
Basically finished
Only small details are still missed in the SC, (GUI FEE th, integration of MB temperature sensors and MB trigger signal rates.)
Integration of the reference chambers for gas monitoring purposes.
7 small RPCs/sector for monitoring purposes
Readout by the same system
Signal multiplexer already included in the RPC sector

16. Intrinsic RPC performance from Aug11 data
Intrinsic RPC performance from Aug11 data
Analysis. No cuts, full multiplicity from raw data. Day 230.
Aug11
Overlapped cells t1
t’1 t2
t’2
Time difference
T = (t1+t2)/2 – (t’1+t’2)/2
Time resolution
σ t= σ(T)/√2
Position difference
X =
Vprop/2 [(t1-t2)/2 – (t’1-t’2)/2] =
Vprop/2[X1-X2]
Longitudinal
position resolution
σ x= σ(X)/√2

17. Intrinsic RPC performance from Aug11 data
Intrinsic RPC performance from Aug11 data
Position and charge information used to correct time 5
Corrected
< σ t> = 111 ps
< σ t> = 104 ps
No corrected
2.5
ΔT (ns)
-0.5 -5
1.5
X1 position (ns)
X1 position (ns)
Corrected
No corrected
< σ t> = 74 ps 1
0.5
0.5
ΔT (ns)
-0.5 -1
Q1 (A.U)
Q1 (A.U)

18. Intrinsic RPC performance from Aug11 data
Intrinsic RPC performance from Aug11 data
Time resolution
Two possible overlaps/cell
Overlap n->n
Overlap n->n+1
σ t (ps)
S4 cosmic GSI, one single column showing the 2 possible overlaps
Row number
Systematic degradation of time resolution for n-n overlap under Row 14, Physical?!?, further investigation needed.
σ t (ps)
Overlap n->n
Overlap n->n+1
S4 Nov10 data and Aug 11, one single column showing the 2 possible overlaps
Row number
In the following only n->n+1 overlap is shown

19. Intrinsic RPC performance from Aug11 data
Intrinsic RPC performance from Aug11 data
Time resolution (n->n+1)
< σ t Global> = 80 ps
< σ t>
All channels have a resolution well below 100 ps S1
81 ps S2
80 ps S3
80 ps
σ t (ps) S4
79 ps S5
82 ps S6
78 ps
Row number

20. Intrinsic RPC performance from Aug11 data
Intrinsic RPC performance from Aug11 data
Spatial resolution
< σ x Global> = 8.9 mm
< σ x> S1
8.7 mm
8.9 mm S2 S3
9.1 mm
σ x (mm) S4
8.8 mm S5
8.1 mm S6
8.6 mm
Row number

21. (Typical gain in timing resolution ~ 10-15 ps σ)
Calibration. Status
INL correction (fundamental for good timing). OK
Calibration of position (inside the cell) and charge. OK
Charge correction. OK (although it needs fine tuning)
(Typical gain in timing resolution ~ ps σ)
Time (ns)
Time (ns)
Parameter
Containers
Charge (fC)
Charge (fC)

22. Calibration . . INL correction (fundamental for good timing). OK
Calibration
INL correction (fundamental for good timing). OK
Calibration of position (inside the cell) and charge. OK
Charge correction. OK (although it needs fine tuning)
Time calibration (offset of individual cells). Calibration with protons. OK

23. Calibration. TOF calibration with protons
Calibration. TOF calibration with protons
To avoid some side effects of the previous ±π calibration (low statistics or lack of π´s in some regions), a new proton-calibration was written, as protons covers almost all the detector surface with high statistics.

24. Raw <TOF> positioned around 8 ns
Calibration. TOF calibration with protons
To avoid some side effects of the previous ±π calibration (low statistics or lack of π´s in some regions), a new proton-calibration was written, as protons covers almost all the detector surface with high statistics.
Raw <TOF> positioned around 8 ns
S2 BC
Raw calibrated
TOF from RPC
<TOF> (ns)
Row number
<TOF> (ns)

25. *assuming all particles protons.
Calibration. TOF calibration with protons
To avoid some side effects of the previous ±π calibration (low statistics or lack of π´s in some regions), a new proton-calibration was written, as protons covers almost all the detector surface with high statistics.
Raw calibrated
TOF from RPC
ToF
Calibration
constant
Momentum (p) and
path length (L)
from R-K
Momentum
cut at 0.9 GeV
(avoid Mult.Scat)
TOF* = L/v =
=L*mp/p
*assuming all particles protons.

26. TOFmeasured- TOFestimated for one RPC cell
Calibration. TOF calibration with protons
To avoid some side effects of the previous ±π calibration (low statistics or lack of π in some regions), a new proton-calibration was written, as protons covers all the detector surface with high statistics.
Peak due protons
Calibration
constant
Failed mass hypothesis
TOFmeasured- TOFestimated for one RPC cell

27. Calibration. TOF calibration with protons
Calibration. TOF calibration with protons
To avoid some side effects of the previous ±π calibration (low statistics or lack of π´s in some regions), a new proton-calibration was written, as protons covers almost all the detector surface with high statistics.
<TOF> after calibration
S1 BC
Raw calibrated
TOF from RPC
ToF
Calibration
constant
Momentum (p) and
path length (L)
from R-K
Momentum
cut at 0.9 GeV
(avoid Mult.Scat)
TOF* = L/v =
=L*mp/p
*supposing all particles protons.
<TOF> (ns)
Row number

28. Calibration. TOF calibration with protons
Calibration. TOF calibration with protons
Full PID plot

29. Calibration. TOF calibration with protons
Calibration. TOF calibration with protons
Full PID plot

30. Full sector system timing resolution at a level of 170 ps σ
Calibration. TOF calibration with protons
Individual cell system timing resolution at a level of 150 ps σ
π – S1 BC13
π + S1 BC13
TOFmeasured- TOFestimated
TOFmeasured- TOFestimated
Full sector system timing resolution at a level of 170 ps σ
π – S1
π + S1
TOFmeasured- TOFestimated
TOFmeasured- TOFestimated

31. Still many “details” to be understood, wok in progress
Calibration. TOF calibration with protons
Still many “details” to be understood, wok in progress
PID plots from Tatyana

32. Calibration . . INL correction (fundamental for good timing). OK
INL correction (fundamental for good timing). OK
Calibration of position (inside the cell) and charge. OK
Charge correction. OK (although it needs fine tuning)
Time calibration (offset of individual cells). Calibration with protons
Fine time calibration (dependence of average time with cell position). Calibration with protons

33. Calibration. TOF calibration Vs. position . .
Calibration. TOF calibration Vs. position
TOFRPC – TOF From momentum
Fine time calibration will correct (at a level of ~ 10 ps σ) the position dependence
Position

34. Calibration. TOF calibration Vs. position . .
Each region will be evaluated individually, following the same procedure as for the full cell.

35. The RPC is almost fully integrated. Only small details still missed.
Conclusions
Hardware is ready for production beam time although small things should be fixed.
The RPC is almost fully integrated. Only small details still missed.
Calibration procedures are basically implemented, but still lot of work should be done.