Status of DT Local Trigger Commissioning

C. Battilana, F.R. Cavallo, S. Marcellini

•YB0, YB+1 and YB+2 fully analyzed and already updated on the commissioning web page

•New computation of trigger efficiency to avoid bias due to geometrical effects

•Discussion and classification of problems

CMS week Dec. 07 1

Local Trigger Efficiency Definition

We want to compute efficiency in MB2:

We require a reconstructed track segment In MB2 with > 6 hits in ± 40 degrees around the perpendicular direction.

We also require another trigger and another track segment in any another barrel station of the same sector

If these conditions occur, we check if there is a trigger at any BX in MB2.

This definition avoid biases which happenin cases when only one station is crossed,for which trigger effic. is by definition 100 %CMS week Dec. 07 2

CMS week Dec. 07 3

Technical trigger: a trigger in at least one station, with a “almost” HanyTheta configuration. “Almost” means that the trigger occurs with HanyTheta, but also Low Triggers are released if the chamber is not triggering

Overview of the Results

S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12

YB0 314 12611 269 17319 12819 13475 349 21643 480 18947 166 15361

YB+1 17562 17588 17613 17846 17613 17596 16517 17501 17547 14668 15134 14345

YB+2 18311 22341 24173 23033 18024 24173 23282 23033 18024 25393 22341 18311

Green OK

Red Low efficiency in all stations.

Purple Low efficiency only in MB4

Black OK but maybe a specific hardware problem

Light blue Other different inefficiency problems

Bold italic underlined (any color) changed during the test

CMS week Dec. 07 4

Case: OKPo

sitio

n

Angle

Efficiency Occupancy

MB1

MB2

MB3

MB4

CMS week Dec. 07 5

Case: OK

Phi effic. vs angle Theta effic. vs angle

HH+HL Phi effic. vs angle H-Theta effic. vs angle

CMS week Dec. 07 6

MB4 has only correlatedtriggers

Case: OK (this is a Sector 4, where MB4 is big and splitted in two parts)

Phi effic. vs position Theta effic. vs position

HH+HL Phi effic. vs position H-Theta effic. vs position

CMS week Dec. 07 7

Dead cell

Case: OKBX

Trigger quality

Phi Triggers Theta Triggers

Best Quality has most entries, and it also defines the “correct BX”

CMS week Dec. 07 8

Case: Low efficiency in all stations Po

sitio

n

Angle

Efficiency Occupancy

MB1

MB2

MB3

MB4

CMS week Dec. 07 9

Case: Low efficiency in all stations

Phi effic. vs position Theta effic. vs position

HH+HL Phi effic. vs position H-Theta effic. vs position

All efficiencies scaled by about 20 %CMS week Dec. 07 10

Case: Low efficiency in all stations BX

Trigger quality

Phi Triggers Theta Triggers

Plots look normal,except Theta triggers in MB4CMS week Dec. 07 11

Case: Low efficiency in all stations

Explanations:

Several cases of doubled events, for what concerns trigger information, as well as swapped trigger primitives between MB1-MB3 and MB2-MB4 (this explains those events with theta trigger primitives in MB4, which are actually coming from MB2.

Also events with no triggers at all, usually in bunches, related to very noisy events.

For all these events there is no matching between TDC-tracks and trigger primitives.

We checked that in runs catalogued as OK, with good efficiency, such bad events are not present, or are just very rare.

These events should not occur with the final DAQ and electronics read-out,and are peculiar of the system used for the test.

CMS week Dec. 07 12

Case: Low Efficiency Only in MB4 Po

sitio

n

Angle

Efficiency Occupancy

MB1

MB2

MB3

MB4

CMS week Dec. 07 13

Case: Low Efficiency Only in MB4

Phi effic. vs angle Theta effic. vs angle

HH+HL Phi effic. vs angle H-Theta effic. vs angle

CMS week Dec. 07 14

Case: Low Efficiency Only in MB4

Nothing strange in the trigger quality

BX

Trigger quality

Phi Triggers Theta Triggers

CMS week Dec. 07 15

Case: Low Efficiency Only in MB4

Explanations:

In run 25393, YB+2, S10, together with the MB4 inefficiency, there are frequent cases with HH quality triggers in MB4, and no TDC track in that station. It might be a sign of bad data.

In runs 269 (YB0, S3) and 349 (YB0 S7) and 18947 (YB0 S10) no strange behaviour is observed, except the MB4 inefficiency. Pierluigi and Cristina suggest it might be a wrong shift (positive instead of negative) wrongly assigned in the configurations.

CMS week Dec. 07 16

Case: OK but maybe a specific hardware problem (YB+1, Sector 2)

The Theta occupancy plot is OK

BUT

H-Theta BTIs are not releases(but L Theta trigger efficiency is 100 %)

CMS week Dec. 07 17

Case: Other different inefficiency problems (S11 YB+1)

Phi effic. vs angle Theta effic. vs angle

HH+HL Phi effic. vs angle H-Theta effic. vs angle

Only H-Theta efficiency is Low.CMS week Dec. 07 18

Case: Other different inefficiency problems (S12 YB+1)

Phi effic. vs position Theta effic. vs position

HH+HL Phi effic. vs position H-Theta effic. vs position

H-Theta effic. Low and different from station to station

HH+HL Phi efficiency is low CMS week Dec. 07 19

Case: Other different inefficiency problems (S12 YB+1)

Theta Quality peaked at Low triggerPhi Quality peaked at HL instead of HH

BX

Trigger quality

Phi Triggers Theta Triggers

CMS week Dec. 07 20

Case: Similar to YB-1, Sector 1 ?

CMS week Dec. 07 21

Some gas problem was observed in this case

Case: Similar to YB-1, Sector 1 ?

CMS week Dec. 07 22

Conclusions

CMS week Dec. 07 23

•In general the trigger performs correctly.

•Several cases of low efficiency seem related to DAQ performances and should not occur in the final system (it can be checked in GREN data)

•A small number of sector with strange behaviour, which should be checked more carefully