lhcc - may 2000 1 the cms alignment system alignment scheme task of the align. system monitor the...
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LHCC - May 20001
THE CMS ALIGNMENT SYSTEM
Alignment scheme
Task of the align. system Monitor the position of the -chambers and the CT detectors with respect to each other.
Building blocks: 4 subsystems- Internal tracker align.- Internal muon : barrel and endcap- The link tracker muons
(3 alignment planes)
Basic components• Mechanical structures (rigid, stable)• Light sources (LED, laser beams)• Light detectors (DPSD)• Tilt, proximity and temp. sensors
System requirements Physics requirements
Position accuracy in r (referred to the tracker detector) for muons up to 2 TeV : - track reconstruction: ~500 m - for pt measurement: ~150(350) m at MB1(MB4)
~150 m at ME1 layer Operational constraintsDetector hermeticityLarge dynamic range (few cm)Radiation tolerance and insensitivity to B of the components
LHCC - May 20002
THE CMS ALIGNMENT SYSTEM
Alignment scheme
LHCC - May 20003
THE CMS ALIGNMENT SYSTEM
Alignment scheme
LHCC - May 20004
MUON ALIGNMENT SYSTEMORGANIZATION AND PARTICIPANTS
Internal Barrel Internal Endcap Link systemCERN (CMT) USA: SPAIN:Hungary (Debrecen) : FERMILAB CIEMAT (Madrid) Kossuth L. Univ. North-Eastern Univ. IFCA (Santander) ATOMKI Austria (Vienna) : HEPHY Inst. Fur H. der OAWPakistan (Islamabad) : Optics Labs.
. . . . . . . . . . . A lig n m en t ... . . . . . .
M u on P ro jec tF . G asp arin i
G . M itse lm akh er
LHCC - May 20005
Link Tracker - Muons
Working principle Translates Tracker co-ordinates (points, angles) to the ´linking points´ in the external MABs
– The tracker co-ords are defined by the internal tracker alignment at the TK ends (TK alignment wheels)– The MAB ´linking points´ serve for Barrel and Endcap connection to the Tracker– Each 1/4 plane is generated independently. The whole system is constrained at the TK volume – Points (3D co-ords) are measured with laser beams + semitransparent sensors for the co-ords
perpendicular to the beams, and by mechanical tubes and proximity sensors for the co-ords along the beams
– The angle is measured at each structure (TK wheel and MABs) by Laser Level units
Measures directly ME1/2 chambers (CSCs crossed by a secondary link line) and the ME1/1 CSC disk (using a ME1/1 transfer platform to bend by 90° the laser beam)
LHCC - May 20006
Barrel muon alignment
Working principle
36 rigid mechanical structures called
MABs are holding TV-cameras
(typically 10 cameras/MAB). These
cameras are observing LEDs
mounted on both sides of the barrel
muon chambers ( 40/chamber) and
on the so called Z-bars (the reference
in Z-direction).
A high level of redundancy is
achieved by multiple observations
and loops which make the system
robust and reliable.
The barrel system is connected to the
TK via linking lines.
LHCC - May 20007
Endcap muon alignmentConnect Endcap CSCs to Tracker• Tracker co-ordinates (points, angles) from the MAB modules (via link
system) • 6 axial lines (transfer lines) pass through the MABs and run outside each
CSC station• Connection between axial lines and SLMs on transfer plates. • Z distance measured by mechanical tubes and optical gap sensors • Radial measurements from transfer plates to CSCs by potentiometers
CSCs alignment design • 3 laser lines per CSC station (SLM) are linked to the axial transfer lines:
– SLM measures location of CSCs (on 1/6)– SLMs are 60 degrees apart, mount on CSCs at same point on each
chamber– Precise location of sensors on CSCs using internal calibration and
photogrammetry– Precise relationship of strips, alignment pins, and sensors on CSCs
LHCC - May 20008
Endcap muon alignment:
Transfer lines and Z measurements Laser
Tracker
MAB
BARREL MUON
Link LineSecondary Link Line
Transfer Line
Sensors
EMU
Fig 2. EMU Transfer-line Schematics
LHCC - May 20009
Endcap muon alignment: SLMs
CSC
LHC Beam
M 1
P 1
M 2
P 2
MAB
EMU Transfer line
EMU Transfer line
CSC SLM-line
SLM sensor
Transfer Sensor
Transfer Plate
ALIGNMENT SCHEMATICS
SLM Laser
2-Dsensor
Transfer Plate
Transfer Laser
Alignment Schematics. Only one transfer laser is shown, at the top-left corner, defining the EMU transfer line. Similarly for the SLM line, only one laser beam, coming from the top is shown. The other laser beams coming from the opposite directions have been omitted for clarity.
LHCC - May 200010
Barrel alignment status
Mechanics: MABs and LED holders Minimal system test Readout electronics
LHCC - May 200011
MAB Modules
(External MABs) Barrel cameras
Link sensors
Endcap transfer sensors
LHCC - May 200012
MAB development
Aluminum prototype used for first tests.
New prototype under construction (Portugal)• Glass fiber 1.5 1 m2 • Study deformations at the junctions (data by June)
define final geometry and materials
3D design of the different MAB structures: most of integration problems (inside the Mu-detector and at boundary region) have been identified.
LHCC - May 200013
LED holders in the MB chambers
- Four forks /chamber - Each fork instrumented with 10 LED (4/6) - LED positions within the holder: 16 m (x,y), 60 m (z) Total number of LED ~ 10000 - Mounting of precalibrated forks and LED
driver electronics during chamber assembly at the production sites.
- Calibration of each chamber at Cern before installation in the detector
Estimated calibration precision: 55-65 m (x,y) 470 m (z)
LHCC - May 200014
LED Holder mechanical repeatability
Deviation wrt to a mean of a series of position-reposition tests
-20
-15
-10
-5
0
5
10
15
20
25
30
0 2 4 6 8 10
Measurement #
Dev
iati
on
to
mea
n (
mic
ron
s)
LED1 X
LED1 Y
LED2 X
LED2 Y
s = 12.6 m
s = 2.6 m
s = 1.3 m
s = 0.6 m
LHCC - May 200015
BARREL alignment stand (CERN ISR I4-hall)
Layout of the Minimal test of the barrel alignment: disposition of alignment
components as for the central muon barrel wheels
LHCC - May 200016
Minimal barrel test results:
Accurate reconstruction of LED positions with a floating calibrated MAB referenced by external system
s(D5) = 18 m
s(D4) = 38 m
s(M5) = 11 m
s(M4) = 25 m
s(G5) = 20 m
s(G4) = 52 m
FORK RECONSTRUCTION IN X (RELATIVE)
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8
MAB POSITION (mm)
FO
RK
CE
NT
ER
PO
SIT
ION
IN X
(m
m)
D5_FORK
D4_FORK
M5_FORK
M4_FORK
G5_FORK
G4_FORK
LHCC - May 200017
Readout electronics
• Bla bla... MAB
Ca
me
ras
(16
to
24
)
Te
mp
era
ture
Se
nso
rs (
4 t
o 1
6)
Board computer
Ethernet
Control room
Slow control
MA
B -
LE
Ds
(0
to
20
)
Z b
ar
- L
ED
s(0
to
4)
Barrel muon chamber slow control unit
Slow control forbarrel muon chambers
CAN
4 LED holders (<20 LED-s/holder)
Chamber
I2C
AMPRO Littleboard P5i (PC104 type)
146x203x30 mm3•100/166 MHz Pentium* processor • PC/AT compatible system on a single board•Up to 128M bytes onboard DRAM •PC/104 with PCI extension•Floppy, IDE, EPP, Parallel, 4 Serial ports•PCI UltraSCSI•PCI Super VGA LCD/CRT local bus controllerwith GUI accelerator•High speed Ethernet LAN interface•Extensive embedded feature set: ruggedizedBIOS, bootable solid state disk, •watchdog timer, powerfail NMI, locking I/Oconnectors, Advanced Power Management•Small size +5V only operation, low powerrequirement, extended temperature operation
LHCC - May 200018
Minimal barrel test results:
Accurate reconstruction of LED positions with a floating calibrated MAB referenced by external system
s(D5) = 18 m
s(D4) = 38 m
s(M5) = 11 m
s(M4) = 25 m
s(G5) = 20 m
s(G4) = 52 m
FORK RECONSTRUCTION IN X (RELATIVE)
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8
MAB POSITION (mm)
FO
RK
CE
NT
ER
PO
SIT
ION
IN X
(m
m)
D5_FORK
D4_FORK
M5_FORK
M4_FORK
G5_FORK
G4_FORK
LHCC - May 200019
Readout electronics
• Bla bla... MAB
Ca
me
ras
(16
to
24
)
Te
mp
era
ture
Se
nso
rs (
4 t
o 1
6)
Board computer
Ethernet
Control room
Slow control
MA
B -
LE
Ds
(0
to
20
)
Z b
ar
- L
ED
s(0
to
4)
Barrel muon chamber slow control unit
Slow control forbarrel muon chambers
CAN
4 LED holders (<20 LED-s/holder)
Chamber
I2C
AMPRO Littleboard P5i (PC104 type)
146x203x30 mm3•100/166 MHz Pentium* processor • PC/AT compatible system on a single board•Up to 128M bytes onboard DRAM •PC/104 with PCI extension•Floppy, IDE, EPP, Parallel, 4 Serial ports•PCI UltraSCSI•PCI Super VGA LCD/CRT local bus controllerwith GUI accelerator•High speed Ethernet LAN interface•Extensive embedded feature set: ruggedizedBIOS, bootable solid state disk, •watchdog timer, powerfail NMI, locking I/Oconnectors, Advanced Power Management•Small size +5V only operation, low powerrequirement, extended temperature operation
LHCC - May 200020
Barrel alignment: summary
Prototypes of components exist: Mechanical design of LED holders and video cameras is ok Final MAB design under development
Neutron irradiation of the opto-electronic components up to highest barrel doses (fluences = 2.6 1012 n/cm2): ok
Magnetic field tests (up to 1T) of cameras, LED, and board computer prototype: ok
Readout electronics (prod. version) under development DAQ + Software test version ready
First test of the system concept ok: consistent with expectations Full simulation of system performance (as for the TDR)
LHCC - May 200021
Endcap alignment status
Mechanical progress Sensor developments DAQ and software
LHCC - May 200022
Mechanical progress and Sensor technology Layout
• Most conflicts resolved:– Required some changes to the disk and cart designs– SLM lines change z position due to RPC chambers layout
• Mount positions on CSCs defined: Prototype mount plates and towers constructed for ME23/2 chamber
• Roughly 50% of transfer plate production drawings finished
Sensor development• The SLM design requires up to 10 sensors in line:
– ALMY: Semitransparent a-Si sensors (see later) – DCOPS: Digital CCD optical position sensor
• 4 linear CCDs mounted in a window frame + cross-hair laser beam
• Readout with DSP processor and serial I/O
• Good test results on resolution & stability
• Radiation test: Test CCDs in 4 MeV proton beam (neutron fluences of 1.3 1013 n/cm2 Present version of the CCD and readout are acceptable (safety factor ~3)
LHCC - May 200023
DCOPS sensor board
LHCC - May 200024
DCOPS neutron irradiation
TABLE 1
Neutron Radiation Dose in 10 Years at CMS
(x3 factor included)
Station Z(mm) R1(mm)Dose in
neutrons/cm2 R2(mm)Dose in
neutrons/cm2 Max
ME1/2 6665 2825 5.9 x 1010 4605 3.2 x 1010
ME1/3 6840 5100 9.8 x 1096800 1.5 x 1010 6 x 1010
ME2/1 7876 1500 3.2 x 1012 3400 3.7 x 1010
ME2/2 7876 3700 2.8 x 10106800 2.6 x 1010 3.2 x 1012
ME3/1 9714 1700 7.5 x 1011 3400 1.3 x 1011
ME3/2 9714 3700 9.4 x 10106800 4.1 x 1010 7.5 x 1011
ME4/1 10620 1900 7.4 x 1011 3400 1.5 x 1011
ME4/2 10620 3700 1.3 x 10116800 8.3 x 1010 7.4 x 1011
At theTransfer plates (R=7250), dose ranges between 3 x 1010 and 8 x 1010
(From K. Maeshima's E-mail 9/23/99, based on numbers supplied by M. Huhtinen)
Table 2
Radiation Test 10/7/99 DataIC # Position # Row Column Exp. Time
Fluence in
n/cm2
A1 1 17 5.5 8hrs 1.2 x 1013
A2 2 17 7.5 " 6.2 x 1012
A3 3 21 9 " 3.2 x 1012
A4 4 25 10 " 1.6 x 1012
B1 15 14 2 1hr 1.9 x 1012
B2 16 13 6 " 6.6 x 1011
B3 17 12 10 " 2.9 x 1011
B4 18 6 11 " 1.2 x 1011
C1 19 2 8 " 7.5 x 1010
C3 31 2 12 8hrs 5.8 x 1011
D1 32 24 5 " 2.8 x 1012
D2 33 27 7 " 1.3 x 1012
laser 001 44 4 2 1 hr 8.5 x 1010
laser 002 45 4 12 " 8.5 x 1010
NOTE: Row and column numbers refer to 'Neutron Fluence Map' (Umass Lowell Radiation Lab)
LHCC - May 200025
CCDs neutron irradiation
CCD Dark Current Vs. Neutron Fluence
y = 96.273x2 + 272.64x
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 1 2 3 4 5 6 7
Neutron Fluence (x 1012 n/cm2)
AD
C C
ou
nt
ADC saturation level
Fig 2. Dark current level (at center of CCD) vs. neutron dose. The relative saturation level is determined by the readout speed (see text).
LHCC - May 200026
DCOPS neutron irradiation
• bbbIrradiated CCDs, Raw Data (DCOPS)
0
500
1000
1500
2000
2500
3000
3500
4000
1 201 401 601 801 1001 1201 1401 1601 1801 2001
Pixel Number
AD
C C
ou
nts
3.2 x 1012 neutrons/cm2
1.6 x 1012 neutrons/cm2
Fig 3. Raw spectra of two of the irradiated CCDs, showing the peaks produced by the laser lines.
-0.06
-0.03
0.00
0.03
0.06
0.00 5.00 10.00 15.00 20.00 25.00 30.00Microtable Position (mm)
Dev
iati
on
(m
m)
RMS: 0.013 mm (visible pts. only)
Irradiated CCD Linearity Test
0
5
10
15
20
25
30
Mea
sure
d P
osi
tio
n (
mm
)
Fig. 4. Linearity test on CCD D1, which was exposed to a neutron dose equal to the 3 times the expected fluence in a 10-year CMS run. Notice that the linear range extend for more than 25mm (from 1.5mm to 27mm). The gaps in the data, at the microtable positions of 6mm and 22mm, are artifacts of the automated data taking setup.
LHCC - May 200027
Endcap DAQ and Software
DAQ system (C++ in window98 env.) has two branches:DCOPS readout chain: • Line of DCOPS boards read out through serial interface
• 1 serial processor / disk
(Note that the read-out DAQ will be very much the same for DCOPS and ALMY)
HP readout chain: • HP readout unit contains all multiplexers, switches and signal conditioning hardware
• 1 HP readout unit /disk
Two steps offline analysis: FLAP (First Level Analysis Program, C++, OO design on UNIX
platform ): • Takes raw data from DAQ as input and fits data to find centroid in CCD pixel numbers.
• Convers HP DC voltage read out appropiate position and temperature units
SLAP (Second Level Analysis Program): • Takes FLAP output as input and converts the CCD centroid pixel numbers to the real space
positions using the position calibration constants
• .... Design in progress
LHCC - May 200028
Link system status
Mechanical progress Sensor developments (ALMYs and Laser Level) DAC system and Software
LHCC - May 200029
Mechanical progress
Layout
• Mechanical drawings in the endcap/barrel region (MAB and ME1/2) ready • ME1/1 transfer and mounts on ME1/1 CSCs prototype drawings exits
• Re-design of the = 3 region in accordance with the EE calorimeter support
• TK region in standby ... (position and size of passage re-defined for new geometry)
• Complete prototypes for the ISR tests (tests of mechanical behaoivor):
Laser box, Laser Level, distance meas (mechanical tube + optical and potentiometers), periscope -short size, ~40 cm-, DPSDs mounts, re-positionings platforms
.
LHCC - May 200030
Sensors develpoment (1) ALMY: Semitransparent a-Si sensors
Performance:Linearity and resolution: 5 m
Sensor fiducilization: ~1 m (2D configuration)
Radiation hardness:
- (CIEMAT) up to 10 Mrad: ok
- n (ATOMKI) total fluence 1015 n/cm2: ok
- p (24 GeV/c PS CERN) total fluence 1013 n/cm2: sensors still cooling down ...
Optical properties: >75 % transmission
Serial readout electronics
New prototypes development:Stuttgart: succeeded to produce test structures with dark currents as low as required. They proceed now
with the fabrication of the first set of complete test sensors with final layout and bonding pads until beginning of July.
This effort is carried out -within CMS- by Spain. It is done in collaboration with the MPI (Munich), institute involved in the alignment of the muon chambers of the ATLAS experiment.
Minnesota: produced (by Feb 2000) two complete prototypes (with identical geometry as the old EG&G sensors). Their optical and electrical properties have been studied at CIEMAT-Madrid.
The electrical test was not satisfactory: the sensors did not show the typical diode curve. Instead, they yield IV curves rather symmetric with respect to the (0,0) point which correspond to two mutually inverted Schottky
barriers. This behavior was understood given the high symmetry of the structure (ITO/intrinsic a-Si/ITO) of the prototypes. Two lines of actions have been identified for the new prototypes to be built.
The optical test was instead rather satisfactory. The measured transmission for both devices was over 75% and quite flat over the whole working region (wavelength 750-900 nm).
New prototypes ( 8 units) will be ready by summer. We will be testing mainly the electrical properties of the junction and charge division between strips, given that the optics is already properly understood.
This effort was supported -within CMS- by US and Spain until beginning of 2000. It will continue mainly by Spanish institutes.
LHCC - May 200031
Semitransparent aSi:H sensors (ALMY) Thickness aSi 1 mThickness electrodes100 nmThickness glass substrate 500 m Number of electrodes 64 horizontal, 64 verticalActive area 20 mm 20 mmStrip pitch 312 m
Low Hall mobility B field insensitiveAmorphous Si Rad. hardnessGlass substrate Multi-point meas.
Título:aSi_3Dbis_eng.epsAutor:fig2dev Version 3.2 Patchlevel 0-beta3Vista previa:No se guardó esta imagen EPSincluyendo una vista previa.Comentario:Esta imagen EPS se imprimirá en unaimpresora PostScript, pero no enotros tipos de impresora.
19 mm dia.
LHCC - May 200032
Sensors develpoment (2) Laser Level units
Consist of:A laser source + a tiltmeter (AGI and AOSI) one or two dimensional
Performance:Linearity and resolution: ~10 rad (independent tilt calibration)
Stability of the assembly: <5 rad
Radiation hardness and insesitivity to B: to be tested
- From manufacters (AGI): ok up to 10 Mrad doses
insensitive to uniform fields, and ok up to 80 gauss/mm
LHCC - May 200033
Tiltmeter (AGI-756) calibration: linearity, resolution and stability
-600
-400
-200
0
200
400
600
-8 -6 -4 -2 0 2 4 6 8
Res
po
nse
(m
V)
a (mrad)
V(mV) = 460.35 mV/mrad a(mrad) - 16.39 mV
Range (mrad) k(mV/mrad) Resolution (rad)(-7,+7) 460.11 1.27 11.1 1.5(-5,+5) 459.58 1.20 10.7 1.5(-3,+3) 458.84 1.58 10.9 2.6
-790
-785
-780
-775
-770
0 2000 4000 6000 8000 1 104
Res
po
nse
(m
V)
Time (min)
-210
-205
-200
-195
-190
-185
0 2000 4000 6000 8000 1 104
Resp
on
se (
mV
)
Time (min)
After stabilization s = 0.6 radTOTAL: 6.7 days
After stabilization s = 1.9 radTOTAL: 6.7 days
LHCC - May 200034
Laser level: calibration and mechanical stability
-230
-228
-226
-224
-222
-220
-218
1.248 104
1.25 104
1.252 104
1.254 104
1.256 104
1.258 104
1.26 104
1.262 104
0 500 1000 1500 2000 2500 3000
AGI1 (mV)
Y_position (microns)A
GI1
(mV
)
Y_position (m
icrons)
Time (min)
s_Y_position = 5.6 rads_AGI1= 5.4 rad
-220
-218
-216
-214
-212
-210
-208
-206
1.312 104
1.314 104
1.316 104
1.318 104
1.32 104
1.322 104
1.324 104
1.326 104
1.328 104
0 1000 2000 3000 4000 5000
AGI1 (mV)
Y_position (microns)
AG
I1 (
mV
)
Y_p
osition (microns)
Time (min)
s_Y_position = 4.4 rads_AGI1= 4.1 rad
LHCC - May 200035
DAQ and Control system + Software
DAC configuration:Level 1: includes sensors and local electronics boards(LEB)
– LEB: microcontroler with flash program memory and data memory + CAN controler chip – The microcontroler is equiped with: ADC convertors to handle the signal coming from the diferent
sensors used (temperatutre, DPSD, tiltmeters,..), a serial port, timers for signal generation and several digital I/O ports to control the 2D position sensors.
It will perform basic treatment of the signals (center of gravity, gaussian fits..)– At the moment each LEB handles up to 4? sensors (any type) sitting at < xx m from the actual devices.
Level 2: comunication via CAN bus between L1 and industrial PC– Each LEB comunicates via CAN bus protocol with the PC using a Main Controler Interface (a CAN
controler board with two ports) placed in the PC – PC for data storage and processing
Level 3: comunication via Ethernet between align. PC and Detector Control System (DCS)
Software:Level 1: LabView (programming graphic platform) for data acquisition and control. Fully developed for system tests
Level 2: CMS OO code for optical alignment (COCOA). Simulation and reconstruction package.(ISR version available)
LHCC - May 200036
Planned activities (Y2000)
Complete test with Link system, Barrel and Endcap alignment (ISR-I4)
The installation of components and DAQ started last week (May 10th)
~ 5 weeks for individual calibration of parts First common data taking by ~ 20 June. The full setup will stay in place up to end of the year
EDR foreseen for October Endorse the general scheme LED holders for the DT chambers first to go into production
LHCC - May 200037
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