Outline

1
Outline

• Introduction
• Alignment scheme
• Organization and participants
• System requirements
• Current status Barrel, Endcap and Link
  subsystems
• Concept and integration
• Components prototypes, calibration, rad. tests
• Electronics and DAQ
• Planned activities
• Project schedule and Milestones

2
THE CMS ALIGNMENT SYSTEM

• Alignment scheme

Task of the align. system Monitor the position
of the m-chambers and the CT detectors with
respect to each other.
Building blocks 4 subsystems - Internal
tracker align. - Internal barrel-m - Internal
endcap-m - The link trackerÛ muons (3
alignment planes)

• Basic components
• Mechanical structures (rigid, stable)
• Light sources (LED, laser beams)
• Light detectors (DPSD)
• Tilt and proximity sensors
• Temp. sensors

3
MUON ALIGNMENT SYSTEMORGANIZATION AND
PARTICIPANTS

• Internal Barrel Internal Endcap Link system
• CERN (CMT) USA SPAIN
• Hungary (Debrecen) FERMILAB CIEMAT (Madrid)
• Kossuth L. Univ. North-Eastern Univ. IFCA
  (Santander)
• ATOMKI
• Austria (Vienna)
• HEPHY Inst. Fur H. der OAW
• Pakistan (Islamabad)
• Optics Labs.

4
SYSTEM REQUIREMENTS

• Physics requirements
• Position accuracy in rf (referred to the tracker
• detector) for high momentum muons
• - track reconstruction 500 mm
• - for pt measurement
• 150(350) mm at MB1(MB4) chambers
• 150 mm at ME1 layer
• Operational requirements
• detector hermeticity
• radiation tolerance and insensitivity to B
• gradients of the components
• large dynamic range (few cm)

5
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
• CT via linking lines.

6
Barrel muon alignment (cont.)

• Integration
• - no conflict with the m chambers
• chambers (HV, gas, connections,
• etc.)
• - no conflict with service cables
• - no conflict in the barrel endcap
• region

• Elements
• - MAB (Module optique pour
• lAlignement du Barril)
• - Z bar
• - Camera boxes
• - LED holders
• - MAB and LED electronics
• - Software

7

• Camera boxes
• Single side, double side, diagonal, Z cameras

• LED holder (fork)

8
Barrel alignment - neutron irradiation

• LED

LED Light emission Barrel pos. 35
degradation Electrical properties ok
LENS Focal length and transmission No change
observed

• VIDEO SENSOR
• Sensitivity and homogeneity
• Barrel pos. 35 degradation (noisy back. in the
  image)
• Characteristics of the VM5402 video camera
  module
• Matrix 384 287 (CCIR) pixels
• Pixel size 12 mm 12 mm
• Sensitive area 4.66 mm 3.54 mm
• DC power 8-12 V

For the barrel Þ image processing studies Þ
development of a LED driver to regulate the input
current
9
Test program
10
Endcap muon alignment
11
Endcap muon alignment (cont.)
ALIGNMENT SCHEMATICS
Transfer Sensor
Transfer Laser
EMU Transfer line


M
M
1
2

SLM Laser
P
1
Transfer Plate
MAB
SLM sensor
LHC Beam
CSC
CSC SLM-line
2-D
P
2

sensor
Transfer Plate
EMU Transfer line
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.
12
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13
Endcap alignment (cont.)

• Design and integration
• Transfer line and ME1 layer design ME1/2 sensors
  and ME1/3 SLM sensors position defined.
• ME2-3-4 SLM universal sensor mounting brackets
  draft calibration procedure and test bench.
• Photogrammetry measurements at production of
  strips - alignment pin - and sensor pin hole.
• Sensor development
• Test of multi DCOPS readout.
• Prototype of bi-directional sensors for redundant
  measurements prototypes ready to test.

14
Endcap planned activities

• Installation of sensor mounts in the P2 chamber
  prototype to test mechanical stability and
  compatibility with cable routing.
• Planning of a full configuration 14 m SLM test
  bench at FNAL (MP9 tunnel) with DCOPS sensors,
  transfer plate system and readout system.
• Neutron irradiation tests of lineal CCDs (ME2/1
  up to 6.4 1012 n/cm2 - 10 years LHC).

15
DCOPS sensor board
16
Link tracker - muons

• Working
• Task principle
• Relate 2 detectors -
  multipoint system- laser beams
• defined by their
  (independent 1/4 f plane)
• align. systems - f independent
  meas
• - distance meas.
• Þ Translate TK ref. to
• LINK points
• (for Barrel and Endcap)
• Þ Refers directly ME1/1 and ME1/2 chambers.

17
Link current status

• COMPONENTS PROTOTYPES
• Light source laser optics (includes a
  repositioning mechanics)
• Periscope (to bypass Si tracker volume)
• a-Si transparent sensors (ALMY)
• Laser levels
• Distance measurements CF tubes (also as light
  protecting tubes) and proximity sensors
• ME1/1 transfer plate
• DAQ SYSTEM
• Software LABVIEW based (tests lab.)
• PC based Serial communication (CAN bus and
  Ethernet)

18
Light source

• Laser source
• - collimator with FC/PC connector
• (laser diode pigtailed to monomode fiber
• wavelength 790 nm, thermal stabilization)
• Optics
• - beam splitter
• - rhomboid prism

Laser box
19
Semitransparent aSiH sensors (ALMY)

• Thickness aSi 1 mm
• Thickness electrodes 100 nm
• Thickness glass substrate 500
  mm
• Number of electrodes 64 horizontal, 64
  vertical
• Active area 20 mm 20 mm
• Strip pitch 312 mm
• Low Hall mobility Þ B field insensitive
• Amorphous Si Þ Rad. hardness
• Glass substrate Þ Multi-point meas.
  

20
ALMY sensors (cont.)

• ALMY AR coating on the back face of the glass
  substrate

21
ALMY sensors rad. hardness

• Radiation levels at ½h½ 3
• Doses up to 1Mrad/year
• Neutron fluxes up to 3 1013 cm-2/year
• Charged particles fluxes 1013 cm-2/year
• Gamma irradiation
• NAYADE facility at CIEMAT (Madrid)
• 60Co sources, 0.3 Mrad/hour
• Irradiation up to 10 Mrad
• Neutron irradiation
• Cyclotron MGC-20 at ATOMKI (Debrecen)
• p(18 MeV) Be
• ltEgt 3.7 MeV, 1.6109 cm-2 s-1
• Negligible gamma content (500 rad)
• Irradiation up to 1014 n/cm2
• Schottky sensors (diode FE electronics)
• optical properties

22
ALMY sensors rad. hardness (cont.)

• No (significant) change observed in optical
  properties
• - The deflected angles remain unchanged
• - Possible degradation, 5 in transmittance
• (with HeNe) after 1Mrad of g
• The sensor response decreases in 10 after 10
  Mrad g and 20 after 1014 n/cm2. The response
  of the irradiated sensor is still within the
  typical values.
• Electronics resistors and capacitors ok. The
  multiplexors die after 20 krad g

23
Link integration

• - Endcap iron and barrel/endcap region
• space allocated, no major problems foreseen
  (needs
• redesign of sensors board geometry for ME1/2 and
  
• MABs)
• - ½h½ 3 region in progress (few
  requirements)
• - Tracker region current status ok (6 alignment
• passages foreseen at the CTS structure)

24
ALMY sensors FE electronics

• Reduced sensor board sizes for the barrel/endcap
  region

25
ALMY sensors (cont.)

• The sensors are well understood and fulfill the
  requirements in all aspects.
• Recently EGG (Germany) has stopped the
  production of sensors. Two new centers Stuttgart
  and Minnesota Univ. are producing new prototypes,
  built with the same specs. The first units are
  expected by the end of the year.

26
Periscope specs. and prototype

• The accuracy of the system depends strongly on
  the definition of the light path, and therefore
  of the calibration and stability of the
  periscope.
• (Tolerance given by the size of passages and
  the sensor active area.)
• Þ Geometry
• Þ Materials
• Þ Optical quality of elements

27
Laser level

• Tiltmeter laser
• linearity of the response
• resolution 9 mrad
• rad. hardness, tested up to 10 Mrad
• insensitive to B gradients up to 80 gauss/mm.

28
Optical elements rad. hardness

• Radiation levels at ½h½ 3
• Doses up to 1Mrad/year
• Neutron fluxes up to 3 1013 cm-2/year
• Charged particles fluxes 1013 cm-2/year
• Gamma irradiation
• NAYADE facility at CIEMAT (Madrid, Spain)
• 60Co sources, 0.3 Mrad/hour
• Irradiation up to 10 Mrad
• Neutron irradiation
• Pakistan Research Reactor (PARR-1)
• Average thermal neutron flux at sample 2.51011
  n/cm2/s ltEgt 0.025eV Fluence 7.5 1013
  n/cm2
• Average fast neutron flux at sample 5 1010
  n/cm2/s ltEgt 1.0 MeV Fluence 1.5 1013 n/cm2
• Later irradiation up to 1014 n/cm2 (no changed
  observed)
• Samples of optical glass, coating and cements
• Transmission and reflection properties
• (measured using a Perkin Elmer Lambda-19

29
Optical elements rad. hardness (cont.)

• From g irradiation
• Fused silica and BK7G18 are ok (0.5 change in T
  and R)
• BK7G18 with broad band AR and R(Ag) coatings are
  ok (0.1 change).
• Cements mechanical stability tests on progress.
• From n irradiation
• Fused silica JGSI, QTZ and Suprasil are ok.
• AR and HR coatings ok.
• Cements NOA61 good optical properties.

30
Project schedule and milestones

• Task list (Milestones L3) to be completed by end
  1999 / February 2000
• - prototypes of the different parts
• - partial tests calibrations
• Milestones L2
• - Minimal barrel test end October 99
• - Electronic prototype end Dec. 99
• - Begin integrated tests
• (at the ISR) December 99
• - EDR June 2000

31
Project schedule and milestones

• Task list (Milestones L3) to be completed by end
  1999 / February 2000
• - prototypes of the different parts
• - partial tests calibrations
• Milestones L2
• - Minimal barrel test end October 99
• - Electronic prototype end Dec. 99
• - Begin integrated tests
• (at the ISR) December 99
• - EDR June 2000