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