Fiber Tracker Update Edward McKigney Imperial College July 3 rd, 2002

Outline Fiber Tracker Description Near-term R&D Program Tentative Milestones Summary

Emittance Measurement (P. Janot)

Fiber Tracker Several planes of crossed scintillating fibers, based on experience with D0 and MuScat Relatively simple technology giving a fast signal

Fiber Tracker Layout Layout based on 0.35 mm or 0.50 mm round doubly clad fibers with a doublet layer structure Three layers of doublets crossed at 120º provide an active area of 30 cm diameter There are a total of 4286 (3000) fibers per detector plane 0.3% (0.4%) X 0 per plane with a resolution of about 40  m (extrapolated from the measured resolution in D0) (A. Bross)

Readout Schematic Mirror Scintillating Fiber Optical connector Waveguide VLPC cassette Electronics Cryostat Or MAPMT System (A. Bross)

VLPC VLPC (Visible Light Photon Counter) –Cryogenic APD 9K Characterization/test/sort Cassette Assignment –As shown (A. Bross)

VLPC Performance (A. Bross) VLPC  HISTE VI –High QE  80% –Low noise <5X10 4 Hz  1.0 pe) –High Rate capability >40 MHz –High production yield  70% (vs. 27% projected)

Important Detector Issues Detectors must operate in strong solenoidal fields & with intense RF-cavity backgrounds & contribute negligible emittance degradation Working out safe design and operating approaches is a crucial and challenging part of the MUCOOL R&D effort underway at Fermilab

Front-End Electronics Current VLPC readout uses SVXII chip, this is being replaced by D0 New electronics will be clocked at 132 nS, and are being designed now; based on a custom ASIC(TriP chip) and commercial ADC and FPGA chips Need to evaluate if these electronics can be used for MICE If we can use the D0 electronics, we just need to order them when D0 does its production, if not new electronics will be a major undertaking

Near Term R&D Prototypes of two versions (.35 mm and.5 mm) of the SciFi ribbons are being made at FNAL – these are 1 inch ribbons with no adhesive in the active region (‘stretched fiber’ design) A test cryostat with 32 VLPC channels is being constructed at FNAL A beam test with muons at KEK will happen in the Autumn Tests with the 805 MHz cavity in FNAL Lab G will happen before Christmas

Conclusions We have a good conceptual design based on round scintillating fibers and VLPC readout Suitability of the new D0 readout electronics needs to be determined Prototypes are being constructed now, and will be tested in a muon beam and with an 805 MHz RF cavity The RF background issue needs to be resolved using a 201 MHZ cavity There is a good deal of mechanical design work, probably 1-2 years FTE