Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo1 CSC detectors for T1  Brief description of the mechanics  Some comments on the electronics  System aspects Gas system and gas distribution Cooling HV …

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo2 Cathode electrodes panels  Honeycomb panels 10 mm thick Nomex honeycomb 0.6 mm thick fiberglass skin (printed board)  Cathode strips design same for both sides of detector Strips will cross at +/- 60 degree angle artwork obtained with printed board technique before gluing skin on panel Easy for board width up to cm Only 1 company (CICOREL) for larger dimensions Final planarity within tolerances (+/- 0.2 mm) Easy to shape boards Two identical boards needed to build one detector

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo3 CSC side A  Wire support frame glued in position Printed board soldering pads Thickness defines anode cathode distance  precise machining  HV distribution and decoupling HV distribution to wires via decoupling resistor At amplifier end small board with decoupling capacitor, protection diodes and resistor  Wires soldered in position, then glued  Wire mechanical tension measured for each wire

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo4 CSC Side B  Fiberglass frame determines exact distance between cathode planes  No HV  slightly smaller dimensions  Provides gas tightness  Gas distribution in the two sides Gas distribution flow test with plexiglas detector and smoke gave uniform gas distribution in the gap  Relative position of the two sides defined by 2 dowels

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo5 Gas distribution  Hollow channel in the two sides  Small holes uniformly distributed  Test with smoke has proven good flow uniformity

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo6 Electronics 1 TOTEM telescope (5 planes) Is NOT equivalent to (from the point of view of R/O): 1 CMS chamber (6 planes) è in TOTEM signals are generated far apart.  CMS system foresees: sample and store with sophisticated analog memory to solve pile-up problems (SCA chip) and cope with trigger latency each cluster strip hit generates 16 data words (for 8 time samples) Fast trigger logic gives “digital” position of cluster with ½ strip precision (an order of magnitude worst than analog read/out) Coincidence of anode (wire) signals to determine timing of track

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo7 Read Out data  channel count for present layout (half- telescope): 3135 anode wires with 3 mm pitch 5249 cathode strips of 5 mm pitch (both cathode planes are read out)  Read out of full detector at each event creates too many data… need data reduction (track selection) at trigger level  Work in progress on detailed definition of plane and telescope concentrator boards To reduce amount of data Maintain information like timing, pile-up etc. Understand which boards need to be redesigned/built

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo8 GAS distribution  Gas mixture prepared in surface (independent gas zone)  Distribution Forward/backward in counting room  Gas lines from counting room via the HF cable tray  In T1 there will be 1 gas line for the 3 detectors in the half-plane (series flow)

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo9 Cooling  All the power dissipated by the electronics inside the magnets must be “removed” using appropriate cooling.  ~200W of power dissipated by the half- plane electronics (1kW for half-telelescope) For the number of channels considered at present  Electronics boards installed on the support separator in which is integrated a water pipe for cooling. T in ~18-20 degrees T out ~25 degrees

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo10 HV - Low Voltage  Each CSC will have individual HV setting capability (on, off, current and volt. protect)  Power must be adequate for largest rate foreseen (~ 30 μA/ channel)  Low Voltage power regulation at plane level  Power …. Total power needed(?) Use same system as CMS … (?)  One rack on the platform on top of HF to house VME crate(s), gas distribution, Low and HV distribution. No transformers! Fringe field ~500 gauss.

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC January 17, 2003TOTEM plenary meeting -Marco Bozzo11 Radiation  All materials employed taken from the list of tested components for radiation.  Generically (to be defined better) dose in T1 is approx two order of magnitude larger than in the CMS CSC.  They can stand … 10 years at  Our detector at most stand 1 year at 10 33