1

Correlation of HO signal with DT

Gobinda MajumderT.I.F.R.

• Reconstruction of muon tracks and extrapolation to HO

• HO signals in different time slices

• Signal and cross talks

• Conclusion

2

Drift Chamber information• Do not have data base for all runs

• Only databases from Run# 2377 (Bon) and Run#2255 (no field for MTCC-I)

• Reconstruct DTRechit → DTRecSegment2D→DTRecsegment4D

• 3.8T field (Run # 2559-2618): Use StandaloneMuon reconstruction code (modified for MTCC, but field map is for 4 Tesla) and then extrapolate to HO (only 30 cm away)– Extrapolation without any information of database

• No field case (Run # 2476-2552): Use low uniform magnetic field (200 Gauss) to reconstruct muon track.

• MTCC-II : 4412-4438 (4T) and 4446-4457 (ZERO) field : Only Ring2 timing are useful. 3986-4020 (3.8T), but many variation of timings and connections.

3

Cosmic ray muon spectrum in MTCC-I

• Muon trigger is only in sector 10 (Vertically downward)• Momentum has to scale down by a factor 3.8/4• Known problem : Ratio of μ+ and μ– are not 1.3• Use muon with P>4 GeV and |θ–π/2|<0.5, |φ+π/2|<0.5, ndof>30

P (GeV) θ (rad)

4

Pixel configuration of Ring1&Ring2

• No difference in Ring1 and Ring2

• Look for signal in nearby six pixel (if there and also readout)

5

Time profile of Sector10, examples

• Variation of timing within few time period

Phase-I YB1

Phase-II YB2 (3.8T)

Phase-II YB1 (3.8T)

Phase-I YB2

6

HO signals and cross talk

• Signals only in Sector-10, φ=270o

• Use only time slice 2-5 for MTCC-I

• MTCC-II : 3-6 for Ring-I and 4-7 for Ring-2

• Pedestal is obtained from a single run, e.g., run# 3986 for data at 3.8T in phase-II

• Signal to the extrapolated HO towers as well as nearest towers (pixel and physical position of tower)

• To check random noise use same pixel in Ring-1(2), when extrapolated muon on Ring-2(1)

• To have better accuracy of extrapolation, events are selected where muon hits inside 10cm of an edge of HO tile

7

Stability of pedestals

• Pedestal values are stable over MTCC run period

Pedestal of all HO pixels for run# 3334-3338

Variation of pedestal for different runs (two of them)

Run # Run #

8

Signal in geometrically nearby tower

η=–1 Φ=–1

η=0 Φ=–1

η=+1 Φ=–1

η=0 Φ=0

η=+1 Φ=0

η=–1 Φ=0

η=–1 Φ=+1

η=0 Φ=+1

η=+1 Φ=+1

• There are some +ve signals in geometrycally nearby towers, due to extrapolation or pixel cross talk or both ?

-10 (fC) 20

-10 (fC) 20

-10 (fC) 20

-10 (fC) 20

-10 (fC) 20

-10 (fC) 20

-10 (fC) 20

-10 (fC) 20

-10 (fC) 20

9

Signal in geometrically nearby tower,but in different RM (ZERO field)

• Projection is not perfect, Muon reco/Extrapolation ?

Projected φ=55

Signal in Φ=56

Projected φ=56

Signal in Φ=55

∆η=–1 ∆η=0 ∆η=+1

fC

fC fC

fCfC

fC

10

Signal in geometrically nearby tower,but in different RM (3.8T field)

• Projection is not perfect, Muon reco/Extrapolation ?

Projected φ=55

Signal in Φ=56

Projected φ=56

Signal in Φ=55

∆η=–1 ∆η=0 ∆η=+1

fC

fCfCfC

fCfC

11

Uncorrelated noise level (muon in YB1,signal in YB2)

• In YB+1 case, we see some noise in presence of magnetic field

B=0 YB=1

B=0 YB=2

B=3.8TYB=2B=3.8T

YB=1

fC

fCfC

fC

12

Signals in towers of nearest pixel, Ring1 without any field (H,15)

• Little signal in nearby pixel

Up left

Up right

ProjectedRight

Left

Bot Left Bot

rightAll six

QADC (fC)

13

Signals in towers of nearest pixel, Ring1 with B=3.8T (H,15)

• Not much cross-talk, but signal height gone down

Up left

Up right

ProjectedRight

Left

Bot Left Bot

rightAll six

QADC (fC)

14

Signals in towers of nearest pixel, Ring2 with 3.8T (H,15)

• Little signal in up-right pixel

Up left

Up right

ProjectedRight

Left

Bot Left Bot

rightAll six

QADC (fC)

15

• Statistical error ~1-3%. Total cross talk is 5-10%.

Phase I data : Sector 10 @ZERO field

16

Phase I data : Sector 10 @3.8T field

• Cross talk increase to ~15% for ring 1

17

Phase II data : Sector 10 @ZERO field

18

Phase II data : Sector 10 @4.0T field

• No visible change in signal and cross-talk

19

Comparison of means with and without B-field

• There is no effect in ring-2, but ring-1 signal has gone down by a factor ~2, whereas cross talk is only about 10-25%

20

Comparison of HO signal and pedestal width in TB2006 & MTCC-I (no filed)

• Signal distribution is fitted with a (Gaussian (for ped)+Gaussian convoluted Landau (signal) in TB2006, for MTCC signal is fitted with only Gaussian convoluted Landau function

TB2006 MTCC

fC

fC

fC

fC

Pedestal Pedestal

Signal Signal

21

• qw

HO signal and pedestal width in TB2006

Sigma peak/sigma

22

HO signal and pedestal width in MTCC(zero field)

• Signal@ZERO field is comparable to TB2006 signal. Though signals are not consistent (in TB06 muons cover more path in the scintillator)

23

Conclusion

• There is negligible cross-talk in Ring-2 pixel (~0.2T)

• Ring-1 pixel shows increase in cross-talk of the level ~10% (0.3T)

• Similarly uncorrelated noise is very low ~4×10–4

• Irrespective of cross-talk, total signal has gone down with magnetic field.

24

• Many test on time slice, half of RM were not connected etc.

25

HO signal and pedestal width in MTCC(3.8T field)

26

27

Angle between Bz/By vs z, important to eliminate HPD xtalk

28

2000, 2003 preditions vs 2006 Hall probe, By

Field value also changes !

Field less than0.2T (2kG) needed to have no discharges in HO

29

Bfield measurements with moving Hall probes (vladimir epshteyn, slava)

YB/1

-0.5-0.4-0.3-0.2-0.1

00.1

0 500 1000 1500 2000

Distance, mm

B, T

Bx By Bz

YB/2

-0.8

-0.6

-0.4

-0.2

0

0.2

-2500 -2000 -1500 -1000 -500 0

Distance, mmB,

T

Bx, T By, T Bz, T

Hall probes installed during mtcc1/mtcc2 shutdowndata taken at 3.8T (Wednesday morning, oct-25-2006)And at 4.0T (Monday, oct-31-2006)

0,4T is no good,We want <0.2 T, need to displace box by ~70 cm

70cm