A High Eta Forward Muon Trigger & Tracking detector for CMS

A High Eta Forward Muon Trigger & Tracking detector for CMS

Archana SharmaFor CMS High Eta Upgrade Team (CMS, GDD and RD51)

Oct 8-11, 2010

UPDATE AT RD51 COLLABORATION MEETING BARI

Beam Test Facilities Working Group - WG7

http://www.google.com/imgres?imgurl=http://sdu.ictp.it/openaccess/img/cern_logo.gif&imgrefurl=http://sdu.ictp.it/openaccess/&usg=__BDLbhgsPt6hk-dZWDgUDRjmXIKI=&h=400&w=400&sz=8&hl=en&start=1&tbnid=J2wtlm3dZDECFM:&tbnh=124&tbnw=124&prev=/images?q=CERN+logo&hl=en

CMS Workshop Sep 30, 2010 2

CMS - Redundant Muon System



CMS Workshop Sep 30, 2010

RE1/1

RE1/2

RE1/3

RE2/1

RE2/2

RE2/3

RE3/1

RE3/2

RE3/3

RE4/1

RE4/2

RE4/3

No. of chambers 36*2 36*2 36*2 18*2 36*2 36*2 18*2 36*2 36*2 18*2 36*2 36*2

STAGED

Initial RE system –tailored to budget

Reduced RE system|h| < 1.6

h=2.4

h 2.4

3



RPC Region

Rates Hz/cm2 LHC (1034 cm2/s)

High Luminosity LHC

2.3 x LHC

(1035cm2/s) Phase II SLHC??

RB 30 Few 100 500 Hz - kHz (tbc)

RE 1, 2, 3,4 h < 1.6

30 Few 100 kHz (tbc)

Expected Charge in 10 years

0.05 C/cm2 0.15 C/cm2 ~ C/cm2

RE 1,2,3,4 h > 1.6

500Hz ~ kHz Few kHz Few 10s kHz

Total Expected Charge in 10 years

(0.05-1) C/cm2 few C/cm2 Few 10s C/cm2

Estimated Particle rates in Forward CMS

4



Test Beam setup @ RD51 H4 Prevessin

12000.00

980.0

0

2350

.00

3280

.00

2350

.00

3880

.00

2320

.001100

0.00

980.0

0

920.002050.00

1140.002740.00 1860.00 2520.00

840.00

4440

.00

4700

.00

4880

.00

4600

.00

4510

.00

185.00

4650

.00

4800

.00

FRAME

Scintillators 1 & 2(Upstream)

G1 – Tracker

GEM

G2 – Single Mask Triple

GEM G3 – Tracker GEM

G4 – Timing GEM

G5 – Tracker GEM

Scintillator 3 - downstream

Beam Direction – from left to right direction

5CMS High Eta MPGD - Workshop, 30 September 2010


Prototype Description 1/3

Drift

GEM3T

Anode

3.00 mm

GEM3BGEM2TGEM2B

GEM1TGEM1B

1.00 /2.00 mm

2.00 mm

Drift gap

T1

T2

Induction gap

• GEMs active area: 10 x 10 cm2

• Double mask standard GEM• 1D readout • Gas mixture: • Ar/CO2 (70/30, 90/10)• Ar/CO2/CF4 (45/15/40,

60/20/20)• Gas flow: ~ 5 l/h

1.00 /2.00 mm

Triple GEM (standard)

6CMS High Eta MPGD - Workshop, 30 September 2010



CMS High Eta MPGD - Workshop, 30 September 2010

7

Triple GEM (honeycomb)

HONEYCOMB STRUCTURES

CONFIG. 1: 12mm(Drift) / 12mm(T1) / 12mm(T2) /

12mm(Induction)


12mm(Induction)


0mm(Induction)

The GEM containing honeycomb worked without any problem during the data taking.

Honeycomb will allow to avoid GEM foil stretching!



Drift

GEM3T

Anode

3.25 mm

GEM3BGEM2TGEM2B

GEM1TGEM1B

2.215 mm

2.215 mm

Drift gap

T1

T2

Induction gap

• GEMs active area: 10 x 10 cm2

• Single mask GEM• 2D readout • Gas mixture: • Ar/CO2 (70/30, 90/10)• Ar/CO2/CF4 (45/15/40,

60/20/20)• Gas flow: ~ 5 l/h

2.15 mm

Triple GEM (single mask)

8

This technlogy has been used for large size detector and mass production!


Data Analysis


9

COSTANT Parameters for timing studies

1d readout, strips 0.8mm pitch (vertical to the beam)

Ed=2.0 KV/cm,Et1=Et2=3.0 KV/cm, Ei=3KV/cm

Detector gap configurations

3mm(Drift) 2mm(T1) , 2mm(T2) 2mm(Induction)

3mm(Drift) 1mm(T1) / 2mm(T2) 1mm(Induction)

Efficiency scan with TDC&VFAT

HV Drift scan

HV Induction scan VFAT Threshold&latency

scan

Data-taking


Data Analysis: Timing Studies


10

Standard GEM• Ar(70):CO2(30)• [gaps 3/2/2/2]

Standard GEM• Ar(45):CO2 (15) :CF4 (40)• [gaps 3/2/2/2]

Standard GEM• Ar(45):CO2 (15):CF4 (40)• [gaps 3/1/2/1]

Beam = Muon 150GeV 25kEvt runBeam = Muon

150GeV 25kEvt run

Reached time resolution of 4ns ()

Ei=3KV/cmEt1= Et2 =3.0 KV/cm

Ed=2KV/cmEt1= Et2 =3.0 KV/cm


Data Analysis: Efficiency Studies


11

Standard GEM:• Ar(70):CO2(30) [gaps 3/2/2/2]

Standard GEM:• Ar(45):CO2 (15) :CF4 (40) [gaps 3/2/2/2]

Standard GEM:• Ar(45):CO2 (15):CF4 (40) [gaps 3/1/2/1]

Single Mask GEM:• Ar(45):CO2 (15) :CF4 (40) [gaps 3/2/2/2]

MSPL=4 (100ns) VFAT thr = 25 Beam = Muon

150GeV 25kEvt run

High achievabl

e gain!

Efficiency Plateau


Data Analysis: Honeycomb


12

Honeycomb size

CONFIG. 1: 12mm(Drift)

12mm(T1), 12mm(T2) 12mm(Induction)

CONFIG. 2: 6mm(Drift)

12mm(T1), 12mm(T2) 12mm(Induction)

CONFIG. 3: 6mm(Drift) mm(T1) , mm(T2)

mm(Induction)

Efficiency=50%(data taking affected by grounding problem)

Efficiency=70%GEOMETRIAL FACTORrough est. 65%

Honeycomb will allow to avoid GEM foil stretching!

For RPC spacers take up more than 5% area(1cm circular spacer every 10cm)

Efficiency=70%

Efficiency loss will reduce with bigger cell size


VFAT chip: Introduction

• VFAT chip layout

• Turbo board layout


13

For prototype testing we used electronics developed by INFN (Siena and Pisa), based on the TOTEM VFAT chip.

The VFAT(TOTEM) is a digital on/off chip for tracking and triggering with an adjustable threshold for each of the 128 channels; it uses 0.25m CMOS technology and its trigger function provides programmable “fast OR” information based on the region of the sensor hit.

ANALOG AND ASYNCRONOUS

DIGITAL AND SYNCRONOUS

Without synchronous signal the VFAT introduces a jitter in

the digital output..for more details see Paul slides..


VFAT chip: clock issue


14

VFAT output digital signals are synchronous to VFAT clock (40Mhz, 25ns), therefore the chip is introducing a jitter to the detector signal. This is especially critical when MSPL=1.

Time distribution from GEM (time res=5ns )

VFAT jitter

Jitter&Time distribution convolution

25nsConsidering MSPL=1 (25ns) a gaussian time resolution with rms=5ns will work at full efficiency, the convoluted distribution no!


Simulating LHC conditions


15

In order to remove the VFAT jitter the clock of the chip and LHC should be synchronized to achieve fully efficiency.

..Using experimental data from August Test Beam..

Considering MSPL=1 (25ns) a Gaussian time resolution with rms=5ns will work at full efficiency, the convoluted distribution no!


Final Considerations


16

• The TestBeams (June and August) demonstrated that prototype detectors fulfill all requirements:

High Efficiency

Good performance@LHC

Fast electronics

High Gain

Single mask technology

Good time resolution

• The single mask GEM has been characterized with good performances.

• The honeycomb detector demonstrated to work without problem, good candidate once reached better efficiency performances .

• The detector+electronics works without issues.


OUTLOOK FOR OCTOBERBEAM TEST


17

Test the large area CMS prototype for:Gain uniformity, efficiency, noise, electronics ...

Test small prototype in magnetic field


18

GE1/1 Status and PlansItem Present Status

GEM foils production Done

GEMs HV test 90% finished

Stretching and Framing procedure

90% finished

Drift Electrode Done

HV divider production In progress

HV divider test Pending

Readout PCB production Done

Readout PCB testing In progress

Ready with prototype for 18.Oct.2010

OK


Documents

A High Eta Forward Muon Trigger & Tracking detector for CMS