James L Pinfold University of Alberta 7/8/2009 7/8/2009 James L - PDF document

James L Pinfold University of Alberta 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 1

The MoEDAL Collaboration • The University of Alberta, Edmonton, Alberta (CANADA) - J. L. Pinfold*, R. Soluk, Y. Yao. • The Physics Dept., University of Bologna and INFN Bologna, Viale Berti Pichat 6/2, 40127 Bologna, (ITALY) - S. Cecchini, G. Giacomelli, M. Giorgini, L. Patrizii, G. Sirri, V. Togo • CERN, Geneva (SWITZERLAND) - D. Lacarrere. • Institute of Experimental and Applied Physics (IEAP), Czech Technical University in Prague, Prague, (CZECH REPUBLIC) J. Jakubec, M. Platkevic, S. Pospisil, Z. Vykydal. • Dept. of Physics, University of Cincinnati, Ohio (USA) - K. Kinoshita. • DESY, Hamburg (GERMANY ) - T. Hott • University of Montreal, Montreal, Quebec (CANADA) - A. Houdayer, Claude Leroy. • Northeastern University, Boston, Massachusetts (USA) - J. Swain. • Institute for Space Sciences, P.O.Box MG-23, Ro 077125, Bucharest -Magurele, (ROMANIA)- D. Felea, D. Hasegan, G. E. Pavalas, V. Popa * Spokesman 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 2

The Menu • Introduction • • • Introduction Introduction Introduction • The MoEDAL Experiment • The MoEDAL Experiment • • The MoEDAL Experiment The MoEDAL Experiment – – Detector details – – Detector details Detector details Detector details – Brief overview of Physics Program – – – Brief overview of Physics Program Brief overview of Physics Program Brief overview of Physics Program • • Experimental Issues • Experimental Issues • Experimental Issues Experimental Issues – Safety – – – Safety Safety Safety – – Radiation levels in the VELO Cavern – Radiation levels in the VELO Cavern – Radiation levels in the VELO Cavern Radiation levels in the VELO Cavern – Budget and request for other support – – – Budget and request for other support Budget and request for other support Budget and request for other support – – Construction and installation – Construction and installation – Construction and installation Construction and installation • Collaboration Issues • • Collaboration Issues • Collaboration Issues Collaboration Issues – Interference issues with LHCb – – – Interference issues with LHCb Interference issues with LHCb Interference issues with LHCb – – Organization – Organization – Organization Organization • Conclusion • • Conclusion • Conclusion Conclusion 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 3

Seeking Monopoles Seeking Monopoles at Accelerators at Accelerators ISR p-p E ISR p ISR p-p E ISR p p E cm p E cm cm ~50 GeV cm ~50 GeV ~50 GeV ~50 GeV First accelerator search using NTDs performed at the ISR in 1975 • • DIRECT Experiments - Poles produced and DIRECT Experiments - Poles produced and detected immediately & directly, searches with: detected immediately & directly, searches with: – Scintillation counters & Wire chambers – Scintillation counters & Wire chambers – Plastic NTDs – Plastic NTDs • • INDIRECT Experiments - in which monopoles are: INDIRECT Experiments - in which monopoles are: – Produced, stopped and trapped in matter - (eg beam – Produced, stopped and trapped in matter - (eg beam pipe) pipe) – Later they are extracted, accelerated & detected. – Later they are extracted, accelerated & detected. • • “INDIRECT” Searches where monopoles are “INDIRECT” Searches where monopoles are virtual -in box diagrams virtual -in box diagrams – Results in the production of high energy photon pairs – Results in the production of high energy photon pairs 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 4

Accelerator Based Searches • 31 searches – 14 using plastic Nuclear Ttrack Detectors (NTDs); 3 Using emulsions; 3 using induction; 11 using counters • MoEDAL Collaborators have extensive experience with monopole searches, including, SLIM, MODAL (LEP), MACRO, and several other searches mentioned in the above list. 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 5

Track Etch Detectors • The passage of a highly ionizing particle through the plastic track-etch detector (eg CR39) is marked by an invisible damage zone along the trajectory. • The latent track is manifested by etching – V B is the bulk rate – V T is the faster rate along the track – The reduced etch rate is p = V T /V B • The reduced etch rate is simply related to the restricted energy loss REL = (dE/dX) E<Emax 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 6

Tracking With Track Etch Detectors • The passage of a highly ionizing particle through the plastic track-etch detector (eg CR39) is marked by an invisible damage zone along the trajectory. • Sheets are aligned by means of dowel holes with an accuracy of ~10 microns • In MoEDAL a monopole track would look for aligned etch pits (~10 microns in size) in multiple sheets (3-9 • We can point the track in the track-etch detector stack to the primary vertex with precision 1cm 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 7

Why Use NTDs? • NTDs are sensitive to magnetic monopoles with n ≥ 1 and a broad range of velocities • It should be completely insensitive to normally ionizing particles (to the level of 1 part in 10 16 )* • It is capable of accurately tracking monopoles • \ and measuring their properties (Z/ β ) – Resolution on track in stack ~10microns per point – Pointing resolution to vertex ~1cm. • It doesn’t need high voltage, gas, readout or a trigger • NTDs are not affected by magnetic fields • The calibration of NTDs for highly ionizing particles is well understood • It is relatively radiation hard – ~2 MRad for CR39 – ~200 Mrad for Makrofol/Lexan • It easily covers the solid angle in a very cost effective way * For ∫ Ldt =10 40 cm 2 + rapidity interval of ∆ y = 2, there will be ~10 16 MIPs thru the detector 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 8

MoEDAL MoEDAL MoEDAL • The MoEDAL detector is housed in the VELO Cavern of the LHCb Detector at Point 8 LHcb LHCb 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 9

MoEDAL Experiment MoEDAL-array LHCb RICH LHCb VELO • MoEDAL is an experiment dedicated to the search highly ionizing exotic particles at the LHC, using plastic track-etch detectors (aka NTDs) • We can measure up to a ~7 TeV mass monopole with charge up to ~3g (g is the Dirac charge) • Due to make an initial deployment in 2009, with full deployment of detectors in 2010-11 - running in pp mode at a (nominal) luminosity of 2 x10 32 cm -2 s -1 � ���������������������� = 9 (layers) x 25 m 2 (area in VELO cavern) = 225 m 2 Minimum Z/ β threshold (for CR39) is ~ 5 • 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 10

Basic Detector Element CR39 3 sheets each 500 µ m MAKROFOL 3 sheets each 500 µ m Aluminium face plate 25 x 25 cm • BASIC UNIT – 3 layers of Makrofol (each 500 mm thick) – 3 layers CR39 (each 500 mm thick) – 3 layers of Lexan (each 200 mm thick) – Sheet size 25 x 25 cm • Two etching conditions have been defined: – Strong etching: 8N KOH+1.25% Ethyl alcohol 77 ° C 30 h – Soft etching: 6N NaOH+ 1% Ethyl alcohol 70 ° 40 h • CR39 threshold: – “soft”etching Z/β~ 7 - REL ~ 50 MeV cm 2 g -1 – “strong”etching Z/β~ 14 - REL ~ 200 MeV cm 2 g -1 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 11

Mounting the MoEDAL Detector Array • MoEDAL detectors are deployed in aluminium housings attached to a aluminium frame attached to the VELO Cavern wall • Attachment of frame to wall (above left) and the attachment of housing to frame(above right). • The complete MoEDAL detector set can be removed and installed quickly - within two working days 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 12

Track-Etch Detector Test Deployment 75 cms 50 cms • In the summer of 2008 two MoEDAL housings were deployed using the mounting system described • Each 50cm x 75cm x 2cm housing contains 6 (25cm x 25cm x 1.2cm) MoEDAL plastic stacks. • LHCb reported no problems with the mounted detectors • Several Dosimeters were deployed in the MoEDAL/VELO region on & around the MoEDAL prototype housings to ascertain radiation levels. 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 13

Calibration of MoEDAL NTDs Calibration is performed using heavy -ion beam ������������������ ������������������ �������������������������� �������������������������� MoEDAL NTDs have excellent charge resolution • Calibration at high energy heavy-ions sources is preferred eg BNL, CERN • But if these sources are unavailable low energy ion sources can be used eg: – CHIBA Japan - 300-400 NeV/nucleon – Low energy heavy-ion soures at University de Montreal • The MoEDAL Collaboration has experience with both types of calibration 7/8/2009 7/8/2009 James L Pinfold LHCC Open Session 14