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

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

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).

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

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

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.

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.

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

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.

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

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

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)

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)

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

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

Intrinsic RPC performance from Aug11 data . . Intrinsic RPC performance from Aug11 data Analysis. No cuts, full multiplicity from raw data. Day 230. Aug11 (Au+Au)@1.1AGeV 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

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 -5 -4 -3 -2 -1 0 1 2 3 4 5 -5 -4 -3 -2 -1 0 1 2 3 4 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)

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 test @ 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

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

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

(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 ~ 10-15 ps σ) Time (ns) Time (ns) Parameter Containers Charge (fC) Charge (fC)

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

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.

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)

*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.

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

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

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

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

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

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

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

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

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

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.