Status of the Barrel Alignment –
Comparision of 0T–3.8T movement to Survey
This project is supported by the Hungarian National Research Fund (OTKA) No.: NK67974
Bencze György, Béni Noémi, Szillási Zoltán, Ujvári Balázs
(ATOMKI, RMKI, University of Debrecen)
(on behalf of the Barrel Alignment group)
Muon Barrel Workshop, 2011.05.05.
2011.05.05. 2
• Presentation of the Survey results on target moving between 0T and 3.8T
• Calculation of Survey targets’ drift from reconstructed MAB positions
• Calculation of Survey targets’ drift from Z-bar measurements
• Comparision of results
Outline:
• We know from previous studies (see Barrel report on 2010 Aug Barrel WS) PG
is recovered from Barrel reco at 0T
• 3.8T PG is not possible
We want to see whether relative movements are beliveable or not…
Motivation:
ΔZ MEASURED BY THESURVEY GROUP
2011.05.05. 3
Measurement of the Survey Group
4
Measurement of the Survey Group
5
Measurement of the Survey Group
6
Measurement of the Survey Group
7
First order model for 0T 3.8T
2011.05.05. 8
P P’ P”
Assume no deformations
in Zglobal
)sin(),( fit
obj
ntranslatioR
RAZRZ
fit by thegiven parameters :,,
fitin objects of radius average)(:
fitntranslatio
obj
AZ
R
Objects (MABs, Z-bars)
define planes.
Plane movement can be
fitted over object ΔZ.
ΔZ BASED ON RECONSTRUCTION OF THE MABS
2011.05.05. 9
Gap -3
102011.05.05.
Gap -2
112011.05.05.
Gap -1
122011.05.05.
Gap +1
132011.05.05.
Gap +2
142011.05.05.
Gap +3
152011.05.05.
Fit parameters
2011.05.05. 16
Gap ΔZtranslation A φfit
-3 1,7 -0,47 0,49
-2 1 0,28 4
-1 -0,042 -0,056 -0,12
+1 0,075 -0,12 -0.13
+2 -1,1 0,46 1,5
+3 -1,7 0,55 0,91
MABs for wheel +/- 2
2011.05.05. 17
Near side Far side
DZ [mm] DZ [mm]
Calculated tosurvey position
SurveyCalculated tosurvey position
Survey
YB-2 1 2,638226458 3,6
YB-2
2,151049997 3
YB-2 2 2,638201875 3,6 2,15108667 3
YB-2 BC 2,622194261 3,9 2,063044264 3
Avg 2,632874198 3,7 2,121726977 3
YB+2 1 -2,705395167 -2,3
YB+2
-1,730380193 -2,3
YB+2 2 -2,70536284 -2,3 -1,7303424 -2,3
YB+2 BC -2,734807869 -2,4 -1,615142019 -2,6
avg -2,715188625 -2,33333 -1,69195487 -2,4
982.144.4542
97.9003
mab
survey
obj R
R
R
R
MABs for wheel +/- 1
2011.05.05. 18
Near side Far side
DZ [mm] DZ [mm]
Calculated tosurvey position
SurveyCalculated tosurvey position
Survey
YB-1 1 1,558789558 0,4
YB-1
1,076178643 0,2
YB-1 2 1,558827354 0,3 1,076201761 0,1
YB-1 BC 1,572187976 0,6 1,017896415 0,2
Avg 1,563268296 0,433333 1,05675894 0,166667
YB+1 1 -1,708817669 -0,9
YB+1
-0,69237305 0
YB+1 2 -1,709184033 -0,9 -0,692288965 -0,3
YB+1 BC -1,780205631 -0,9 -0,613077562 -0,2
avg -1,732735778 -0,9 -0,665913192 -0,16667
982.144.4542
97.9003
mab
survey
obj R
R
R
R
ΔZ BASED ON Z-BAR MEASUREMENTS
2011.05.05. 19
Z-bar measurements on YB±2
ZLED1
ZLED2
ZLED3
ZLED4
ZLED5
ZLED6
IP ZLED1
ZLED2
ZLED3
ZLED4
ZLED5
ZLED6
Camera local X
Camera
loc
al Y
+φCMS
on posZ side+φCMS
on negZ side +ΔX -ΔX -ΔY
YB+2 +Δφ -Δφ to IP
YB-2 -Δφ +Δφ to IP
+
+YB moves (with MAB) instead of Zfork(changes sign in φ, but not in Z due to an other trafo.)
What camera observes:‘Real’ life:
p.20
Z-bar Gap-3
212011.05.05.
Z-bar Gap+3
222011.05.05.
Fit parameters
2011.05.05. 23
Gap ΔZtranslation A φfit
-3 1,9 -0,76 0,01
+3 -1,8 0,44 0,67
174.2646.4140
97.9003
barz
survey
obj R
R
R
R
Z-bar
2011.05.05. 24
Near side Far side
DZ [mm] DZ [mm]
Calculated tosurvey position
SurveyCalculated tosurvey position
Survey
YB-2 1 3,28664716 3,6
YB-2
3,30591252 3
YB-2 2 3,28642578 3,6 3,30595325 3
YB-2 BC 3,18062808 3,9 3,20332695 3
Avg 3,25123367 3,7 3,27173091 3
YB+2 1 -2,7928608 -2,3
YB+2
-2,1310475 -2,3
YB+2 2 -2,7928546 -2,3 -2,1310162 -2,3
YB+2 BC -2,7945946 -2,4 -2,0342285 -2,6
avg -2,7934367 -2,33333 -2,098764 -2,4
2011.05.05. 25
Comparision
Comparision of Survey results to the calculated Survey points
Errors:
Survey: ±0.5 mm
MABs : ±800x√2/ √6 ~ ±0.5mm
Z-bar : ~ ±0.5mm
Z-bars and MABs are very much
compatible with Survey (except
passive MABs on YB ±1 Near
Conclusions
2011.05.05. 26
• Comparision of relative movement of Survey targets to reco’d MABs and Z-bars done
• Z-bars are in complete accordance to the Survey results
• MABs are in accordance to Survey results
• Analyis on chamber data is still to be done
• ΔYglobal movements will be determined from chamber data
• we are working on to constrain MAB/DT reco with Z-bars data (not easy, though!)