The LHCf experiment Measurement of Photons and Neutral Pions in the Very Forward Region of LHC Letter Of Intent: May 2004 Technical report: September 2005 Technical Design Report: February 2006 The physics goals are worthwhile and the proposed experiment appears suited to achieve them A few key issues require immediate consideration, and documentation in the update of the TP: establish official contact with the relevant structures in the AT/AB departments, as well as in ATLAS and formulate a complete and costed installation and operation plan, with a commonly agreed checklist, milestones and timeline appoint a technical coordinator (possibly located at CERN?) consider and document safety issues LHCC October 2005 comments:

Experimental Method: 2 independent detectors on both sides of IPX INTERACTION POINT Beam line Detector II Tungsten Scintillator Silicon  strips Detector I Tungsten Scintillator Scintillating fibers 140 m 1.Redundancy 2.Background rejection (especially beam-gas) 3.Physics single diffractive/double diffractive

Detector location Y Chamber

Detector #1: transverse projection Hamamatsu MA-PMT for scintillating fibers PMTs for WLS fibers 4cm 3cm 2cm BEAM AXIS Scintillating fibers WLS fibers to readout plastic scintillators 130 mm 90 mm R7400U E5780

Detector #2 4 cm 3 cm 2 cm 6.4 cm W + Sci Silicon SciFi are replaced by silicon  strips 64x64 mm 2 Pitch 160  m 3 double layers (x-y) 1 double layer in front of the calorimeter Si Sci+W Si

LHCf: replace first 3 copper bars

The TAN for the luminosity monitor Photos taken On April 25 th, 2005 At CERN

Choice of the Interaction Region IP8 (LHCB) or IP1 (ATLAS) were identified in 2004 IP1 was definitely chosen by LHCC in October 2005 Detectors on both sides symmetrically wrt interaction point LHCf will be installed before the LHC startup (May 2007) ‘Ideal’ running conditions: 43 Bunches Low luminosity (~10 30 cm -2 s -1 ) ≤ 1 year data taking period Detectors will be moved up and down by remote control (during beam setting operations) Few general comments

Modifications of the TANs (before February 2006?) to: install manipulator remotely controlled install minicrates for the electronics install additional shielding on top of the TAN to protect the detectors in ‘parking position’ Operations required on the LHC infrastructures (1)

Shield Minicrate Manipulator Mechanical drawings of interconnections between TAN and manipulator, minicrates and shielding should be done a.s.a.p. to drill holes before TAN installation in tunnel

Modifications of the TANs (before February 2006) to: install manipulator install minicrate for the electronics install additional shielding on top of the TAN to protect the detectors in ‘parking position’ Cables (to be pulled before February 2006?): Power lines DAQ lines (optical fibers) Analog signals for trigger Slow controls Cables for manipulator Water cooling for the electronics 220 V ? Operations required on the LHC infrastructures (2)

LHCf and LUMI monitor inside TAN LUMI monitor inside TAN is beyond LHCf (replacing 4th copper bar) LHCf Lumi Cu Bar / ZDC IP1 LHCf Lumi Cu Bar / ZDC LHCf  54 X 0 thickness Beam Pipe is shaped to have a projected thickness of 1 X 0 on 10 x 10 cm 2 region LUMI Monitor see different thickness of material depending on the LHCf position (one of the LHCC concerns!!!!) We are studying the problem of the LUMI calibration together with W.C. Turner and his group from LBNL

Technical coordinator at CERN starting from December 2005 Strict contact with TS/LEA and LEMIC Strict contact with Atlas experiment Electronics crates in USA15 Cables in the Atlas zone Trigger Demande Installation Cables (DIC) in preparation Engineer Change Request (ECR) in preparation for all the TAN and LHC related activities The next steps…

The calorimeter in the test experiment Scintillating Fibers Scintillators plane Size: 9.6 cm x 29 cm x 55 cm