1. Status of the Roman Pot Project reminder prototyping & testbeam mechanics & infrastructure simulation Hasko Stenzel ATLAS week October 2006

2. Roman Pot status H.Stenzel, October 2006 2 Roman Pots for ATLAS RP IP 240m RP PMT baseplate optical connectors scintillating fibre detectors glued on ceramic supports 10 U/V planes overlap&trigger Roman Pot MAPMTs FE electronics & shield Roman Pot Unit

3. Roman Pot status H.Stenzel, October 2006 3 testbeam: October 3-18 Purpose: Verify detector performance observed in 2005 at DESY (6 GeV e - ) with new(larger) detectors, new ATLAS-type electronics with a high energy beam. New prototypes: ●10 planes, U&V, 16 fibres  tracking ●2 planes, U&V, 64 fibres  final geometry ●2 overlap detectors, 120 fibres each  alignment ●trigger scintillator  elastic L1 Program: ●hit multiplicity & efficiency ●cross talk ●spatial resolution & homogeneity ●edge sensitivity & active surface ●alignment performance with overlap detectors ●trigger efficiency & uniformity Purpose: Verify detector performance observed in 2005 at DESY (6 GeV e - ) with new(larger) detectors, new ATLAS-type electronics with a high energy beam. New prototypes: ●10 planes, U&V, 16 fibres  tracking ●2 planes, U&V, 64 fibres  final geometry ●2 overlap detectors, 120 fibres each  alignment ●trigger scintillator  elastic L1 Program: ●hit multiplicity & efficiency ●cross talk ●spatial resolution & homogeneity ●edge sensitivity & active surface ●alignment performance with overlap detectors ●trigger efficiency & uniformity

4. Roman Pot status H.Stenzel, October 2006 4 detector prototypes for testbeam 2006 10 x 2 x 16 resolution studies 2 x 2 x 64 construction studies 2 x 2 x 30 overlaps Fabrication of prototypes at cern bt PH/DT2 with support from Lisbon (LIP) for  fibre machining, aluminum coating, QC  testbeam mechanics and from Giessen for  gluing of fibres  optical connectors

5. Roman Pot status H.Stenzel, October 2006 5 QC: Metrology Fibre ends of 10_2_16 after machining at 45º < 20µm variation from one plate to another prototype 2005: > 250 µm variation

6. Roman Pot status H.Stenzel, October 2006 6 overlap detector: new technology Section to be bent Preheat from room temp to 85ºC Bend fibres at 85ºC Straight section A. Mapelli

7. Roman Pot status H.Stenzel, October 2006 7 trigger scintillator scintillator photomultiplier light guide New design of trigger scintillator with lightguide coupled to a PMT.

8. Roman Pot status H.Stenzel, October 2006 8 electronics: final set-up fibre  MAPMT  PMF(MAROC)  MotherBoard  DAQ

9. Roman Pot status H.Stenzel, October 2006 9 electronics: testbeam set-up PMF Build Up for testbeam October HV board Adapter board Active board MAROC chip R/O FPGA MAROC R/O chip R/O FPGA CERN, Orsay (MAROC) & Lund (PMF & MB)

10. Roman Pot status H.Stenzel, October 2006 10 The final ATLAS Roman Pot Unit ●Pre-production of one unit at Vakuum Praha ●expected at CERN Oct.31 ●will be instrumented and tested ●review of the tests before production ●possible timescale : 4 units at CERN April-May 2007

11. Roman Pot status H.Stenzel, October 2006 11 Pre-production unit Courtesy of Vakuum Praha

12. Roman Pot status H.Stenzel, October 2006 12 The final Roman Pot Overlap extrusions brazed on bottom Top flange with helicoflex joint Pumping hole Rectangular body out of center Brazing under test S.Mathot (TS-MME) Prototyping & production at CERN TS Material for prototype & final production arrived Oct.2 Prototyping Oct/Nov 2006 final production sync. with Unit procurement

13. Roman Pot status H.Stenzel, October 2006 13 Infrastructure: Cable installation Reminder – cabling list: Quantity NameStartEndType/side of IP1Total TriggerXRP-240USA15FLEXWELL Air Dielectric Cable, HF 7/8" 48 Data link + TTCXRP-240USA15Optical fiber for data and TTC (9 fibers/side) 24 LV powerUSA15RRs3x4CEM12 LV power controlUSA15RRsND3624 LV powerRRsXRP-2402x25CEM48 LV powerRRsXRP-2402x4CEM48 HVUSA15XRP-240Mulcitonductor HV cable, 3kVdc,48 FE controlsUSA15XRP-240EIA/TIA RS48548 ELMBUSA15XRP-240VE18CAN-1.024 Motor controlUSA15XRP-240NG1824 Limit switchesUSA15XRP-240NE2624 ResolverUSA15XRP-240NE1824 Position sensorsUSA15XRP-240NE4824 Overlap detector trigger XRP-240USA1550Ohm signal816 BPMsXRP-240RRsCMC5048

14. Roman Pot status H.Stenzel, October 2006 14 Infrastructure: Cable installation Installation of all cables through UPS galleries is now completed on both sides of IP1 ●Access to the UPS galleries is not allowed anymore due to the installation and calibration of the instruments for the geometers. ●HV multiconductor cables are to be installed, different path via US to UX, depending on the location of HV power supplies (US15) Air-core cables – min. bending radius of 250mm respected Optical fibers

15. Roman Pot status H.Stenzel, October 2006 15 Q4 polarity switch RR13 Level 1 RR13 Level 0 DFBLA RQ4.L1B2RQ4.L1B1 inverter 7kA Christophe Coupat AB/PO Switch for Q4 quadrupole to change its polarity when switching from normal to ATLAS/Lumi optics. Base & cabling are completed. Temporary Cu plates ordered, will be installed soon Buying the switch itself can be done later

16. Roman Pot status H.Stenzel, October 2006 16 Simulation of the LHC set-up elastic generator PYTHIA6.4 with coulomb- and ρ-term SD+DD non-elastic background, no DPE beam properties at IP1 size of the beam spot σ x,y beam divergence σ ’ x,y momentum dispersion beam transport MadX tracking IP1  RP high β * optics V6.5 including apertures ALFA simulation track reconstruction t-spectrum luminosity determination later: GEANT4 simulation

17. Roman Pot status H.Stenzel, October 2006 17 Simulation of elastic scattering t reconstruction: hit pattern for 10 M elastic events simulated with PYTHIA + MADX for the beam transport  special optics  parallel-to-point focusing  high β*

18. Roman Pot status H.Stenzel, October 2006 18 acceptance Global acceptance = 67% at yd=1.5 mm, including losses in the LHC aperture. Require tracks 2(R)+2(L) RP’s. distance of closest approach to the beam Detectors have to be operated as close as possible to the beam in order to reach the coulomb region! -t=6·10 -4 GeV 2 decoupling of L and σ TOT only via EM amplitude!

19. Roman Pot status H.Stenzel, October 2006 19 t-resolution The t-resolution is dominated by the divergence of the incoming beams. σ’=0.23 µrad ideal case real world

20. Roman Pot status H.Stenzel, October 2006 20 L from a fit to the t-spectrum inputfiterror correl ation L8.10 10 26 8.151 10 26 1.77 % σ tot 101.5 mb101.14 mb0.9%-99% B18 Gev -2 17.93 Gev -2 0.3% 57% ρ0.150.1434.3%89% Simulating 10 M events, running 100 hrs fit range 0.00055-0.055 large stat.correlation between L and other parameters

21. Roman Pot status H.Stenzel, October 2006 21 experimental systematic uncertainties Currently being evaluated  beam divergence  detector resolution  acceptance  alignment  beam optics ΔL/L ≈ 1.9-2.1 % missing: background studies (are under way) total error ≈ 2.6-2.8 %

22. Roman Pot status H.Stenzel, October 2006 22 conclusion ●testbeam 2006 is starting, preparations in full swing ●new prototypes produced, including overlaps and trigger ●electronics set-up close to ATLAS ●RP units and pot prototypes are under production ●major cable installation effort ●progress on simulations for TDR ●testbeam 2006 is starting, preparations in full swing ●new prototypes produced, including overlaps and trigger ●electronics set-up close to ATLAS ●RP units and pot prototypes are under production ●major cable installation effort ●progress on simulations for TDR