1 / 23

Muon Detector

Muon Detector. Jiawen ZHANG 16 September 2002. BESIII m Detector.

wynn
Download Presentation

Muon Detector

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Muon Detector Jiawen ZHANG 16 September 2002

  2. BESIII m Detector • Them detector is the outmost subsystem of the BESIII detector. It includes detectors and hadron absorbers. Its main function is to identify muons from pions and other hadrons in the momentum range of 0.4—1.5GeV/c and to provide the solenoid flux return

  3. The Detector Choices The Resistive plate counters (RPC) Advantages • Small dead region • Fast response • Lower cost • No poisonous material in case of fire

  4. Simulation Careful simulation studies were made for initial designing and optimizing • Geant 3.21 • Condition • 13 radiation lengths CsI, • all of the other inner detectors equal to 4cm Fe plate

  5. m detection efficiency and p contamination Increase the position pricisoin, considering the p interaction with Fe which can produce second class of particles, and, in turn, produce more than one hit, the p contamination can be reduced in the low momenta Efficiency % Radial thickness of Fe (cm)

  6. m hits position distribution The sigma of the hit position distribution of moun will be about 4 to 8cm after moun’s multiple scatters in the absorber Fe. In this case, improving the position distinguish will not help the separation of moun and pion well but increasing the electronic channels and cost. Hits position s(cm) Radial thickness of Fe (cm)

  7. The structure and detector design Requirements lHigh detection efficiency for muons. lLarge solid angle coverage. l Wide momentum range (the minimum momentum ～400MeV). lHigh rejecting factor for other charged particles. l Suitable position precision.

  8. General structure • Sandwiched structure with Fe as absorber material and RPC • The barrel counters are subdivided into 8 sectors, and 9 layers • inner radius is ~1.7m and outer radius is about ~2.6m • Length 4.1m，(RPC length 3.8m) • 8 layers Fe 3, 3, 3, 4, 4, 8, 8 and 8cm (Total thickness 41cm)

  9. Barrel Structure • Two layers RPC composed from several parts, and they overcast to reduce the dead space

  10. End cap m counter • Each end cap m counter is divided 4 pieces Each end, the 4 pieces are separated to two parts and supported at left or right and each part has its own railway for moving • 8 layers of RPCs

  11. RPC Structure • The structure of RPC Like CMS

  12. Small prototype and the Spacer

  13. Prototype and the Strip

  14. RPC Q Distribution • Ar:F134A: Iso-butane = 30:58:12 • HV=8400V

  15. Gas System • Gas Mixtures Ar+Isobutane+F134A Need some R&D • Mass Flow Control System

  16. High Voltage System • Separate apply positive voltage to the anodes and negative voltage to the cathodes • The modules typically operate with a total gap voltage of 8 KV

  17. Readout System

  18. FEC (Most of the FEC card’s properties have been described before) Shift Out discriminater discriminater discriminater discriminater Anti-errorcode shaper Anti-errorcode shaper Anti-errorcode shaper Anti-errorcode shaper Buffer(XN) Buffer(XN) Buffer(XN) Buffer(XN) Ch00 Ch01 SHIFT REG Ch02 Ch15 Shift In Trigger System Clock Controller

  19. The Expected performance • 0.4GeV/c may be the low momentum limit to identify m • cos q ~0.89 • efficiency ~ 95%

  20. m detection efficiency and contamination from p versus momentum Good m/p separation can be obtained with momenta greater then 0.6GeV/c. With momenta less then 0.5GeV/c, the separation becomes worse. And with momenta less then 0.4GeV/c, the m efficiency is rather lower. So 0.4GeV/c may be a low momentum limit to identify m.

  21. Read out channels • Strips between the double layers RPC • One dimension readout • Strip width 4cm • Readout channels Barrel 48×8×5＋96×8×4=4992 End cap 64×4×2×9=4608 Total 4992＋4608=9600

  22. Schedule • 2001,Oct.—2003,May：R&D, Design and Lab. construction. • 2003,Jun.—2005,Oct.：Chamber production and test. • 2005,Nov.—2006,May：Installation.

  23. THANKS

More Related