LHC Luminosity Monitor in RHIC Run 6 Run

LHC Luminosity Monitor in RHIC Run 6 / Run 7 Brief report on last run Status Plans for this run A Angelika A Drees, A. Ratti APEX Workshop, Nov 2, 2006

LUMI - Conceptual Design Argon Ionization Chamber V+ NGAP=2 I 0 = x. GAP/v. D x. GAP • Signal is proportional to the number of parallel gaps • Capacitance add up with n. of gaps + slows down the signal Optimized for 6 gaps Must live in a radiation environment 100 x worse than accelerator instruments have ever seen

Detector Parameters

LUMI monitor – Installation in the LHC DAQ TAN FE electronics located behind TAN (shown here for illustration purposes)

Installation in RHIC IR 10 between the ZDC behind DX magnet Beam

History Run 6 ● ● Detector installed prior to run 6 HV connector standards different BNL-LBL (lessons learned) gas leak detected, detector shipped back to LBL, repaired and shipped back. design changed first data taking in June 06 w. protons at Ge. V, 110 ns spacing – noise problems (shielding), pick-up from beam – ZDCs were not operational (in progress now) – one channel found shorted inside the chamber (repaired) – installed computer for DAQ w. remote reset

Noise Problem (w. beam) 5 MHz/div 20 db/div 9. 5 MHz 19 MHz 28 MHz 46 MHz

Noise w. and w/o beam no beam, 1 rev.

Status and Plan for Run 7 ● detector is repaired and ready to be shipped back (soon) ● ZDCs are in the process of being “revived” ● move gas system out of the tunnel: likely not possible (manpower) ● install Lab. View daq system and get a new HV supply ● time-in ZDCs with early beam/collisions (expert needed) ● collide in IR 10, either parasitically or dedicated – ● special time (APEX) needed in dedicated case Au-running much more appealing since n-energy is compatible with LHC p-running and well above noise floor of the detector ● establish detector performance ● measure collision rate and cross-calibrate with ZDC ● determine background sensitivity and reliability of measurement