the TOTEM Experience with Triple GEM TOTEM T

the TOTEM Experience (with Triple GEM) TOTEM & T 2 Crew April 18, 2012 CMS GEM Upgrade Workshop III

Important Premises… to keep in Mind • TOTEM is running only in special beam condition (Low Luminosity) (we are most of the time in stand-by / off). • The TOTEM T 2 (Triple GEM) Telescope is roughly at z ± 13. 5 m. • The h region covered by T 2 is 5. 3≤|h| ≤ 6. 5… Very Forward. April 18, 2012 CMS GEM Upgrade Workshop III 2

TOTEM Detectors RP: Elastically (or quasi) Scattered Protons T 1, T 2: Charged Particles in Inelastic Events T 2 Triple GEM 5. 3≤|h| ≤ 6. 5 T 1 CSC 3. 1≤|h| ≤ 4. 7 RP 220 mt RP 147 mt April 18, 2012 CMS GEM Upgrade Workshop III 3

TOTEM T 2 Physics T 2 Contribution to the TOTEM Physics • Total Cross Section Measurement • d. NCh / dh • Diffractive Physics April 18, 2012 CMS GEM Upgrade Workshop III 4

TOTEM T 2 Triple GEM Telescope • Triggering and Tracking Capabilities • h coverage: 5. 3 -6. 5 • j coverage: 360 o • Readout Granularity: • dr ≈ 400 mm [pitch] • dj = 2. 9 o [pitch] • 4 quarters with 10 detectors aligned each. About 99. 5% of all non diffractive minimum bias events and 84% of all diffractive events have charged particles within the acceptance of the TOTEM detectors, T 1 and T 2. April 18, 2012 CMS GEM Upgrade Workshop III 5

TOTEM T 2 in open/close position Δϕ=192 o Sensitive Area April 18, 2012 CMS GEM Upgrade Workshop III 6

Joao Rodrigues Antunes’ Picture TOTEM T 2 & IP 5 A detector on a human scale…. ½T 2 Length ≈ 0. 4 VEL ½T 2 weight < 1 VEW(!) ½T 2 Ext. Circumf. ≈ 1 VEH VEL = Virgina’s Length (height) Equivalent VEW = Virgina’s Weight Equivalent VEH = Virginia’s Hip Equivalent April 18, 2012 CMS GEM Upgrade Workshop III 7

TOTEM T 2 Physics: Preliminary Results • Total Cross Section Measurement • d. NCh / dh • Diffractive Physics V. Avati - LHCC, March 2012. 1. TOTEM: Status & Results. V. Avati (CERN). On behalf of the TOTEM Collaboration. LHCC Open Session April 18, 2012 CMS GEM Upgrade Workshop III 8

TOTEM T 2 Physics: Preliminary Results Measurement of the forward charged particle pseudorapidity density in pp collisions at √s = 7 Te. V with the TOTEM experiment CERN-PH-EP-2012 -106; • Total Cross Section Measurement (1. ) • d. NCh / dh • Diffractive Physics T 2 d. NCh / dh (1. ) V. Avati - LHCC, March 2012. 1. TOTEM: Status & Results. V. Avati (CERN). On behalf of the TOTEM Collaboration. LHCC Open Session April 18, 2012 … e bravo il nostro Mirko Berretti CMS GEM Upgrade Workshop III 9

TOTEM T 2 Physics: Preliminary Results • Total Cross Section Measurement • d. NCh / dh • Diffractive Physics S. Giani, “TOTEM Physics – Results and Perspectives” LHC Seminar, November 22, 2011 CERN April 18, 2012 CMS GEM Upgrade Workshop III 10

TOTEM T 2 Triple GEM R&D, info, construction, quality control. . April 18, 2012 CMS GEM Upgrade Workshop III 11

TOTEM T 2 Triple GEM • R&D The TOTEM T 2 Triple GEM has been designed following the R&D done by CERN GDD group & COMPASS … therefore, a personal thanks to all of them. April 18, 2012 CMS GEM Upgrade Workshop III 12

TOTEM T 2 Triple GEM TOTEM Readout Plane (*) significant in terms of charge sharing April 18, 2012 “Naked” TOTEM Triple GEM TOTEM GEM Foil Strips (r): 512 strips 2 j sectors of 256 each 400 mm pitch, 80 mm width mean cluster size(*) ≈ 2. 5 -3 Pads ( triggering & j ): 1560 pads 65 j sectors of 24 each dj = 2. 9 o, dh = 0. 05 mean cluster size (*) ≈ 1. 2 -1. 5 CMS GEM Upgrade Workshop III Fully Equipped TOTEM Triple GEM 13

TOTEM T 2 Triple GEM • Construction Same procedure as for the COMPASS triple GEM April 18, 2012 CMS GEM Upgrade Workshop III 14

TOTEM T 2 Triple GEM • Construction in the Helsinki Facility All the TOTEM detectors (40+10 spares) has been built by the TOTEM Helsinki Group in their Lab, where Quality Monitor & Basic Measurements have been done. K. Kurvinen, “TOTEM T 2 GEM Production & Quality Control in Helsinki”, 11. 9. 2007 April 18, 2012 CMS GEM Upgrade Workshop III 15

TOTEM T 2 Triple GEM • GEM Foil Quality Control Quality control - Optical scanning (T. Hilden) Leakage current measurements of GEM foils K. Kurvinen, “TOTEM T 2 GEM Production & Quality Control in Helsinki”, 11. 9. 2007 April 18, 2012 CMS GEM Upgrade Workshop III 16

TOTEM T 2 Triple GEM • Readout Board Quality Control Semi-automatic capacitance measurement system R. Lauhakangas K. Kurvinen, “TOTEM T 2 GEM Production & Quality Control in Helsinki”, 11. 9. 2007 April 18, 2012 Relative capacitance measurement from pin to pin (10 min/connector). GPIB-controlled LCR meter, XYZ table and fan-out card with a 130 pin mating connector. CMS GEM Upgrade Workshop III 17

TOTEM T 2 Triple GEM • Basic Measurements Fe 55 X-Ray (Cu) Current Measurements K. Kurvinen, “TOTEM T 2 GEM Production & Quality Control in Helsinki”, 11. 9. 2007 April 18, 2012 CMS GEM Upgrade Workshop III 18

TOTEM T 2 Triple GEM & the TOTEM VFAT 2 FE April 18, 2012 CMS GEM Upgrade Workshop III 19

T 2 & VFAT 2 FE Triggering and tracking synchronous front-end ASIC designed primary for the TOTEM experiment and characterized by: • Preamplifier-shapercomparator readout chains (128) to detect signals above a programmable threshold. • Fast-OR lines (up to 8) that merge channels of programmable sectors to provide a trigger signal. April 18, 2012 CMS GEM Upgrade Workshop III 20

TOTEM T 2 Triple GEM & VFAT 2 • Pads Efficiency(*) vs Gain (*) Dead Channels / Dead Zones (sectors, spacers) Correction Missing April 18, 2012 CMS GEM Upgrade Workshop III 21

TOTEM T 2 Triple GEM & VFAT 2 • Strips Efficiency(*) vs Gain (*) Dead Channels / Dead Zones (sectors, spacers) Correction Missing April 18, 2012 CMS GEM Upgrade Workshop III 22

TOTEM T 2 Triple GEM & VFAT 2 Totem Triple GEM – g 1 T 2 • Cluster Size Pad CLS ≈ 1. 4 Ar/CO 2 70/30 Strips CLS ≈ 2. 6 H. V. Idivider=720 m. A Totem Triple GEM – g 1 T 2 Pad CLS ≈ 1. 5 Strips CLS ≈ 3. 0 Gain ≈ 104 Efficiency (*) 0. 976 0. 984 0. 972 0. 991 April 18, 2012 Err 0. 007 0. 006 0. 008 0. 005 Detector Id g 1 T 2 Pads g 1 T 2 Strips g 2 T 2 Pads g 2 T 2 Strips (*) Dead Channels / Dead Zones (sectors, spacers) Correction Missing CMS GEM Upgrade Workshop III 23

TOTEM T 2 Triple GEM & VFAT 2 • Spatial (Radial) Resolution = 2 s 2 Strips s Strips ≈ 0. 163/√ 2=0. 115 mm s 2 obs Pitch/√ 12 = 0. 4 mm/ √ 12 =0. 115 mm April 18, 2012 CMS GEM Upgrade Workshop III 24

TOTEM T 2 Triple GEM & VFAT 2 • Time Resolution For a LHC running Triple GEM with faster response see LHCb moun system… Bencivenni et al. Asynchronous Beam. Correction needed to compensate the internal VFAT synchronization with the 40 MHz clk April 18, 2012 CMS GEM Upgrade Workshop III 25

TOTEM T 2 & IP 5 Environment Total Ionising Dose (TID) IP 5 Measurement Federico Ravotti “First radiation background studies for the TOTEM Roman Pot and T 2 detectors” Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, 1124 - 1131 April 18, 2012 CMS GEM Upgrade Workshop III 26

TOTEM T 2 & IP 5 Environment • Total Ionising Dose (TID) [Measured] Federico Ravotti “First radiation background studies for the TOTEM Roman Pot and T 2 detectors” Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, 1124 - 1131 April 18, 2012 CMS GEM Upgrade Workshop III 27

TOTEM T 2 & IP 5 Environment • Total Ionising Dose (TID) Federico Ravotti “First radiation background studies for the TOTEM Roman Pot and T 2 detectors” Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, 1124 - 1131 April 18, 2012 ≈ 1 – 2 k. Gy/fb-1 (Sensors) [0. 1 – 0. 2 MRad/fb-1 ] ≈ 5 – 10 k. Gy/fb-1 (Inner Radius) [0. 5 – 1 MRad/fb-1 ] CMS GEM Upgrade Workshop III 28

Radiation Hardness & Aging • Radiation Hardness and Aging - two different aspects • Radiation Hardness Dose • Effects of radiation on material properties (mechanical properties, conductivity, …) • Reference Number: Dose • Aging Dose & Avalanche (Detector has to be ON) • Formation and accumulation of polymers or other chemical processes occurring in the avalanches • Reference Number: Total accumulated charge TOTEM T 2 “Normally OFF” - Low Luminosity Run - 2 nd point less critical than 1 st one April 18, 2012 CMS GEM Upgrade Workshop III 29

Radiation Hardness • Kapton (mechanical properties) H. Schönbacher et al, “Compilation of radiation damage test data : cable insulating materials ”, CERN-79 -04 … fine, I will not convert them in fb-1(? !) April 18, 2012 CMS GEM Upgrade Workshop III 30

Radiation Hardness • Kapton (conductivity) Experimental measurement of XRays induced Kapton conductivity: G. Croci, “Development and Characterization of Micro-Pattern Gaseous Detectors for HEP applications and beyond” PHD Thesis April 18, 2012 wide collimator (5 cm diameter) Dose Rate: 280 Rad/s CMS GEM Upgrade Workshop III 31

Radiation Hardness • Araldite 103 Two type tested in (1. ), unfortunately not our type but…. 500 fb-1 (*) (1. ) F. Guarino, “Compilation of radiation damage test data” 4. CERN-2001 -006. 131 p. April 18, 2012 (*) I’m practically sure that I did some mistake somewhere in the estimation(!? ) … CMS GEM Upgrade Workshop III 32

Radiation Hardness 1 ab-1 (*) • Araldite 103 (*) I’m practically sure that I did some mistake somewhere in the estimation (!? )… (1. ) F. Guarino, “Compilation of radiation damage test data” 4. CERN-2001 -006. 131 p. April 18, 2012 CMS GEM Upgrade Workshop III 33

Aging & Radiation Hardness • All the Aging /Rad. Hard Studies that we used as a reference have been done by CERN, GDD, Compass, R&D experiments as RD 10, RD 28, …. and not directly by us. April 18, 2012 CMS GEM Upgrade Workshop III 34

Aging • Aging and Radiation Hardness - two different aspects • Aging Dose & Avalanche (Detector has to be ON) • Radiation Hardness Dose April 18, 2012 CMS GEM Upgrade Workshop III 35

Aging Single Wire: - An extremely clean SW (i. e. not affecting by itself the measurement ) -Very sensitive to Aging (cathode and anode deposit). GEM: - Aging processes present (as revealed by the SW) but not affecting the GEM gain. S. Bachmann et al. “Development and test of large size GEM detectors” IEEE Trans. Nucl. Sci. NS-47 (2000) 1412 April 18, 2012 CMS GEM Upgrade Workshop III 36

Aging …As found in many experiments, data collected at high current densities tend to be optimistic, often by a large factor, compared to those obtained at lower rates… F. Sauli, “Fundamental understanding of aging processes: review of the workshop results” NIM A 515 (2003) 358– 363 M. C. Altunbas et al. “Aging measurements with the Gas Electron Multiplier (GEM)” Nucl. Inst. Meth. A 515 (2003) 249– 254 April 18, 2012 Measurement performed at two different rate 6. 3 x 103 Hz/mm 2 [2. 5 n. A/mm 2] 2. 5 x 104 Hz/mm 2 [10 n. A/mm 2] 7 m. C/mm 2 Nominal effective gain of 8. 5 x 103 8. 9 ke. V X-ray beam Gaussian profile (s=20 mm) CMS GEM Upgrade Workshop III 37

Aging • 7 m. C/mm 2 for T 2 Integrated Luminosity = 1 fb-1 Inelastic Cross Section ≈ 75 mb N. of Inelastic Events ≈ 7. 5 x 1013 N. of Tracks in T 2 per Inelastic Event @ 7 Te. V ≈ 100 N. of Primary electrons per MIP (Ar/CO 2 70/30 – 3 mm drift) ≈ 30 e. Detector Gain ≈ 104 N. of collected electrons per MIP ≈ 3 x 105 e. T 2 Area ≈ 103 cm 2 Collected electron density per Inelastic Event ≈ ≈ 100 x (3 x 105 e- ) / (1000 cm 2 ) ≈ 3 x 104 e-/cm 2 The T 2 Integrated Luminosity is in the hundreds of mb-1, nb-1 scale. April 18, 2012 Collected electron density per 1 fb-1≈ ≈ (3 x 104 e-/cm 2 ) x 7. 5 x 1013 ≈ 2. 2 x 1018 e-/cm 2 ≈ … ≈ 3. 5 m. C/mm 2 CMS GEM Upgrade Workshop III 38

Aging • Glue: Araldite 103 Detector Seminar: “A high-performance tracking system for the LHCb spectrometer” by Antonio Pellegrino (NIKHEF), September 16, 2011, CERN S. Bachmann et al. , “Ageing in the LHCb outer tracker: Phenomenon, culprit and effect of oxygen”, Nucl. Instr. and Metth. A, Volume 617, Issues 1– 3, 11– 21 May 2010, Pages 202 -205 "ARALDITE AY 103 -1" TWO-PART ADHESIVE RESIN vs "ARALDITE AY 103" TWO-PART ADHESIVE RESIN TOTEM CERN Store Epoxy Orders April 18, 2012 CMS GEM Upgrade Workshop III 39

Aging • Glue: Araldite 103 S. Bachmann et al. , “Ageing in the LHCb outer tracker: Phenomenon, culprit and effect of oxygen”, Nucl. Instr. and Metth. A, Volume 617, Issues 1– 3, 11– 21 May 2010, Pages 202 -205 April 18, 2012 CMS GEM Upgrade Workshop III 40

Aging • Glue: Araldite 103 S. Bachmann et al. , “Ageing in the LHCb outer tracker: Phenomenon, culprit and effect of oxygen”, Nucl. Instr. and Metth. A, Volume 617, Issues 1 – 3, 11– 21 May 2010, Pages 202 -205 April 18, 2012 Intensity = 1 n. A / (1 x 0. 5) cm 2 = 2 n. A/cm 2 Exposure =20 h = 7. 2 x 104 s Accumulated Charge ≈ 1. 5 m. C/mm 2 In T 2: 3. 5 m. C/mm 2 1 fb-1 Actual T 2 TOTEM Integrated Luminosity ≈ 10 -6 -10 -7 fb-1 T 2 Normally Off (low high voltage) – Continuously Flushed (3 l/h). . . and we have not a wire, but a GEM (no panic therefore…. ) CMS GEM Upgrade Workshop III 41

TOTEM T 2 & IP 5 Environment 1 -Me. V neutron equivalent particle fluence (Feq) IP 5 Measurement Federico Ravotti “First radiation background studies for the TOTEM Roman Pot and T 2 detectors” Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, 1124 - 1131 April 18, 2012 CMS GEM Upgrade Workshop III 42

TOTEM T 2 & IP 5 Environment • 1 -Me. V neutron equivalent particle fluence (F ) [Measured] eq Federico Ravotti “First radiation background studies for the TOTEM Roman Pot and T 2 detectors” Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, 1124 - 1131 April 18, 2012 CMS GEM Upgrade Workshop III 43

TOTEM T 2 & IP 5 Environment • 1 -Me. V neutron equivalent particle fluence (F ) eq Federico Ravotti “First radiation background studies for the TOTEM Roman Pot and T 2 detectors” Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, 1124 - 1131 April 18, 2012 CMS GEM Upgrade Workshop III 44

5. 5 Me. V n 2. 8 x 105 n/s cm 2 Discharge Probability [@ Triple GEM Gain = 5 x 104 ]≈ 10 -7 Triple GEM and Neutrons • Discharge Probability Neutrons & Triple GEM studies : G. Croci, “Development and Characterization of Micro-Pattern Gaseous Detectors for HEP applications and beyond” PHD Thesis April 18, 2012 CMS GEM Upgrade Workshop III 45

5. 5 Me. V n 2. 8 x 105 n/s cm 2 Background Rate ≈ 10 -5 interactions/n Triple GEM and Neutrons L = 1034 s-1 cm-2 s. Inelastic ≈ 75 mb • Background (Triple GEM activation) RInelastic ≈ 7. 5 x 1012 Hz Fn < 109 s-1 cm-2 [CASTOR] T 2 Minus Area ≈ 500 cm 2 Neutrons & Triple GEM studies : G. Croci, “Development and Characterization of Micro-Pattern Gaseous Detectors for HEP applications and beyond” PHD Thesis April 18, 2012 Rbackground ≈ 5 x 106 Hz CMS GEM Upgrade Workshop III 46

Some general comments…. • TOTEM T 2 Triple GEM General Status Today • Discharges, Dead Sectors, Dead Channels, …. • TOTEM T 2 Triple GEM @ High Luminosity • hv sectors, protection resistors, … • TOTEM T 2 Triple GEM & Ions Run • Dynamic Range • TOTEM T 2 Triple GEM … one of the most important lesson (at least for me) April 18, 2012 CMS GEM Upgrade Workshop III 47

TOTEM T 2 Triple GEM General Status Today • Discharges (big enough to trigger the tripping): . Only at the beginning • Dead HV Sectors (Shorts) Dead Sector (short): . Only at the beginning. Less than 10 over 480 (40 detectors, 3 GEM per detector, 4 hv Sectors per GEM) • Dead Readout Channels . Localized (most of them in 1 st foil, ext. sector – foil defect/assembly? ) Dead Channels (Readout): . No comment/warning from analysis. Good Detector (discharge normally in foil) & Good Chip Protection (if used? ) April 18, 2012 CMS GEM Upgrade Workshop III 48

TOTEM T 2 Triple GEM @ High Luminosity GEM HV Sectors has to be designed taking into account not only the “safe store energy” but… April 18, 2012 CMS GEM Upgrade Workshop III 49

TOTEM T 2 & Ions Runs V. Avati - LHCC, March 2012. 1. TOTEM: Status & Results. V. Avati (CERN). On behalf of the TOTEM Collaboration. LHCC Open Session April 18, 2012 CMS GEM Upgrade Workshop III 50

CMS/TOTEM Trigger Rate Ratio TOTEM T 2 & Ions Runs April 18, 2012 CMS/TOTEM Trigger Rate Comparison CMS trigger rate = 1. 7/1. 8 k. Hz I 1, I 2 = 3. 34 x 1012, L = 2. 6 x 1026 1 (PN&CMS)/CMS (PF&CMS)/CMS 0. 8 (MF&CMS)/CMS IHV Divider=725 m. A 0. 6 0. 4 0. 2 0 0 100 200 CMS GEM Upgrade Workshop III 300 400 T 2 Triple GEM Gain 51

TOTEM T 2 & Ions Runs Trigger Rate vs T 2 HV [200 ns_358 b_356_336_0_24 bpi 15 inj_IONS] Rate[Hz] CMS Rate T 2&CMS 1. 5 E+04 1. 0 E+04 5. 0 E+03 1. 0 E+00 550 570 590 610 630 IHV Divider=725 m. A High Voltage [u. A] April 18, 2012 CMS GEM Upgrade Workshop III 52

TOTEM T 2 Triple GEM … one of the most important lesson (at least for me) Most of the problem that we had, were not coming from the detector itself. Cooling, Cabling, Connections… because of the intrinsic complexity of our system (limited space, radiation level, …). Now that we know the environment, our system, etc. …. It would be different. Partially because probably we have not chosen the proper solutions in the past and partially Cables, Connectors, Cooling, Gas System, Power… all this kind of things needs the proper attention… and time to time it is better to be less cool (ambitious) and more robust and simple… well, be cool is good … … but also cooled is important … fine, I’m joking… be cool and ambitious April 18, 2012 CMS GEM Upgrade Workshop III 53