TOTEM experiment at the LHC TOTEM physics T1&T2 detector Roman Pot First results Conclusions Joachim Baechler CERN PH-Department on behalf of the TOTEM collaboration http://totem.web.cern.ch/Totem/ 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TOTEM physics Total cross section Elastic cross section  Special LHC settings - optics - luminosity 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

- Measurement of total cross section Forward multiplicity Diffractive physics TOTEM detectors integrated in CMS (T1, T2) TOTEM detectors integrated in LHC (RP) Using luminosity from CMS Luminosity independent ρ parameter from compete fit TOTEM physics program: TOTEM (stand alone) & TOTEM+CMS 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TOTEM detector system CHALLENGE T1 & T2 integrated in CMS Protons are transported in LHC beam-pipe from IP 5 to the Roman Pot stations Roman Pot : detector enters for measurement inside the LHC beam tube CHALLENGE TOTEM has interface to CMS and LHC T1 5 planes of CSC Chambers (wire & cathode strips T1 & T2 integrated in CMS Roman Pot integrated in LHC T2 10 planes of GEM Chambers (pads&strips) 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TOTEM T1 detector - CSC (integrated in CMS) 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

T1 detector system installed during LHC winter shutdown 2010/2011 CMS T1 in SPS-H8 beam line T1 detector before insertion in CMS T1 detector After insertion in CMS Successfully tested with pion and muon beams Both arms were completely assembled and equipped in the test beam line H8 Both arms installed in CMS Minimal distance to beam pipe : ~25 mm Fully operational since spring 2011 beam pipe 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

T1 performances Chamber efficiency Eff [%] +1 Plane +2 +3 +4 +5 –5 –4 –3 –2 –1 (includes read-out effects) Each hit is reconstructed as triple coincidence of one wire and two strips signals Track reconstruction requires hits in 4 out of 5 CSC planes S. Minutoli : Front End, Trigger, DAQ and Data Management - Poster Session: The electronics system of the TOTEM T1 telescope “Raw” η distribution zvertex s = 3.4 cm yvertex xvertex σ = 110 cm Vertex reconstruction No correction for efficiency, acceptance, resolution 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

T2 Detector (triple GEM) Triggering and Tracking Capabilities h coverage: 5.3-6.5 j coverage: 360o Readout Granularity: dr ≈ 400mm [pitch] dj = 2.9o [pitch] 4 quarters with 10 detectors aligned each Number of tracks in inelastic event @ 7 TeV ~ 100 Area of T2 ~ 103 cm2 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TOTEM T2(GEM detector) in CMS open closed 5.3 < || < 6.6 10 detector planes on each side of the IP to cope with high particle fluxes. 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TRIPLE GEM - T2 (E. Oliveri) Totem Triple GEM Cluster distribution Ar/CO2 70/30 H.V. Idivider=720mA (E. Oliveri) Strips (r): 512 strips 2 j sectors of 256 each 400mm pitch, 80mm width mean cluster size(*) ≈ 2.5-3 Pads ( triggering & j ): 1560 pads 65 j sectors of 24 each dj = 2.9o, dh = 0.05 mean cluster size (*) ≈ 1.2-1.5 T2 integrated luminosity is on µb-1, nb-1 scale Collected electron density per 1 fb-1 ~ 3.5 mC/mm2 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TOTEM VFAT Triggering and tracking synchronous front-end ASIC designed primary for the TOTEM experiment and characterized by: Preamplifier-shaper-comparator 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. 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Physics results T2 dNCh / dh Measurement of the forward charged particle pseudorapidity density in pp collisions at √s = 7 TeV with the TOTEM experiment CERN-PH-EP-2012-106; T2 dNCh / dh 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TOTEM Roman Pots at LHC at +/- 147m and +/- 220 m from IP5 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Roman Pot edgeless Si-sensor Physics requirement to measure as close as possible to the LHC beam Technical specification of RP Si detector strips – pitch : 66 µm #strips/sensor: 512 Wafer thickness : 300 µm 5 pairs of planes/RP 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Hybrid and assembly “champignon” Assembly of 10 detectors 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

TOTEM Roman Pots installed at LHC Roman Pot unit with motor system (step size: 5 µm) Separation of high LHC vacuum from detector vacuum Secondary vacuum ~ 20mbar Temp : -25 0C LHC beam-pipe RP mother board: interface Si- detectors to outside world: Signal, Trigger,HV,LV Hosts Radmon sensor and PT 100 Roman Pot parking position Roman Pot data taking position RP mother board Typical beam size: 540 µm / 850 µm 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Roman Pot beam based alignment Insertion of RPs complicated and dangerous operation : Risk of beam dump and damage of sensors TOTEM uses and adopted the LHC collimator control application Complex interlock logic (TOTEM-LHC) All movement operations are done form the LHC-CCC Both Roman Pots (top and bottom) are touching the beam edge : Both pots are the same distance (expressed in sigma) from the beam centre as the collimator  Alignment of the RP windows relative to the beam Silicon sensor positions (relative to each other and to the beam) aligned by software methods After this exercise the RPs can be inserted without new alignment 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Physics results (elastic scattering) 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

p-p elastic scattering p-p elastic scattering differential cross-section Acceptance correction Resolution Efficiency Background External luminosity measurement t limit= 2*10-2 GeV2 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Radiation load on TOTEM detectors Active and passive RadMon sensors mounted on RP – T1 – T2 detector for TID and NIEL measurement T2 RP 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

EM coupling of RP Cooling of RP was switched off The temperature in the Roman Pot increases due to the EM coupling with the LHC -> cooling of RPs is mandatory when LHC beam is injected -> modification of evaporative cooling system by integrating a safety mode to operate above dew point in case of vacuum problem Cooling of RP was switched off 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Electrical trigger TOTEM RP (220m) -> CMS Repeater Card (for the LVDS signals) This card receives the 16 LVDS signals, it recovers the amplitude and compensates the frequency dependent attenuation of the cable. Propagation delay is ~1.2 ns per card, Filter tuned for a 70 m long cable segment and 40 MHz clock Electrical trigger installed during LHC technical stop 2011/2012 Commissioned with first LHC beam in 2012 2x 16bit per RP (384bits on total) 8x 70 m of industrial cable per RP (6720m in total) 96 repeaters, 24 repeaters for patch panel (12 isolation cards) J. Kopal, PhD thesis under preparation 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Conclusions First physics results published on p-p elastic scattering, total p-p cross section and forward charged particle pseudorapidity density at √s = 7 TeV EPL, 95 (2011) 41001 EPL, 96 (2011) 21002 EPL, 98 (2012) 31002 All TOTEM sub detectors are installed and fully operational (T1, T2, RP +/- 147m, RP+/- 220 m) All detectors work according to specifications and were operated at LHC (special runs) – - RP were operated at full LHC luminosity at 20 σ Combined runs with T1, T2 and Roman Pots successfully done Installation and commissioning of electrical trigger (RP 220 m) in technical stop 2011/2012 -> allows to trigger CMS for common runs Combined runs with CMS (Heavy Ions, p-p low luminosity) done in 2011 and 2012 The radiation load is not limiting the detector performance 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Outlook RP 220 m –> ß* = 0.6 m Forward physics at high luminosity requires ultra radiation hard Si pixel detectors (>1015 p/cm2) and timing information (< 10 ps) -> Integration of timing detector in Roman Pot detectors at 220m is under study The Si based picosecond timing detector (ongoing developments at Princeton and Rockefeller) is of interest for the RP project. (WORKSHOP ON TIMING DETECTORS - NOVEMBER 29, 30, DECEMBER 1 2010, S, White) 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Backup slides 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Pitch/√12 = 0.4mm/ √12 =0.115mm 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

RP performance Signal = 25,000 e- 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler

Physics results (2) Primary particle definition: charged particle with > 0.3*10-10 s & pt > 40 MeV/c With all requirements: - primary track efficiency ~ 80% - fraction of primary tracks in the “peak” ~ 75%-90% ( dependent) 12/4/2018 12th Pisa Meeting on Advanced Detectors 20-26 May 2012 Isola d'Elba , Italy Joachim Baechler