basic checks of MM in ATLAS

Yousuke Kataoka(University of Tokyo)

Thanks to Marcin for inputs and infos

p129/5/2012 MM meeting

Fill 2621

MBT0_3 (hit count) MBT0_4 (hit count)

decreasing as luminositydrop at beam dump

Time dependence of hit count p2

• Datarun20231 May 12 8:26~23:53 (15h27m) at Fill2621Nevents = 3475467 events Rate~62Hz random trigger (periodical)

• Chamber MBT0_3 and MBT0_4 …”X” strip(resistive,190ch) and “V” strip(66ch) 30 degree

Charge (Q)

time

time bin … 25ns / bin x 21bins

maxq

maxt

Signal shape

• definition of maxq and maxt in this slide

p3

Hit map (count/channel)

• always hit on 4 channels (MBT0_3(X) ch=96, MBT0_3(V) ch=33, MBT0_4(X) ch=96, MBT0_4(V) ch=33)• dip and bump at low, relatively stable at high maxq

always

MBT0_3 (X) MBT0_3 (V)

MBT0_4 (X) MBT0_4 (V)

Veto 4 channels

p4

maxq distribution

After beam dumppedestal

problem?

13ch

33ch

35ch38ch

All channels

5ch

Pick up some channels

contribution of noiseis small (should x10)

Blue~typical

high rate

p5

maxt distribution

After beam dump

13ch

33ch

35ch38ch

All channels

5ch

All channels

200ns(3bit) period wave (~pedestal, baseline?)

p6

Hit multiplicity

• not so dependent on maxq• typically < 10 (noise is single)• some tail of high multiplicity

largest maxq in all channels

Linear plot

p7

Channel correlation Ch1=40 => ch2=56Ch1=50 => ch2=66Ch1=70 => ch2=86ch1 … largest maxq channel

p8

Cross talkch1=50 ch2=66

maxq2 ~ constant fraction of maxq1

Gaussian fit

mean of gaussian

MBT0_3 … 0.15~0.3MBT0_4 … negligible

p9

subtract shape with the fraction

Cross talk correctionQ_corr(t) = Q_org(t) – fraction x Q_source(t) (t=0~20)

p10

After correction

Time difference of hitsX strip V strip

• Timing is correlated• V structure charge diffusing along resistive strip ~ 50ns / ch

difference of channel from largest maxq channel

p11

Correlation between X,V stripsChannel correlation timing correlation

largest maxq channel in both side

• 30 degree overlap make correlation

maxq correlation

p12

X strip

V strip

Correlation between chambersChannel correlation timing correlation

maxq correlation

MBT0_3(X) and MBT0_4(x)

p13

summary

• I briefly looked at MM data in ATLAS - hit rate, hit map, signal properties, channel correlation - cross talk (need to clean up)• work in progress, I should look into details.

p14

backup

R16 (hit count) R18 (hit count)

R13 (hit count)Time difference of hits (trigger)