Fiber Tracker Update

Edward McKigney

Imperial College

Imperial College July 3rd, 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%) X0 per plane with a resolution of about 40 m (extrapolated from the measured resolution in D0)

(A. Bross)

Readout Schematic

MirrorScintillating

Fiber

Optical connector

Waveguide

VLPC cassette

Electronics

Cryostat

Or MAPMTSystem

(A. Bross)

VLPC

• VLPC (Visible Light Photon Counter)– Cryogenic APD

operating @ 9K

• Characterization/test/sort Cassette Assignment– As shown

(A. Bross)

VLPC Performance(A. Bross)

• VLPC HISTE VI– High QE 80%

– Low noise <5X104 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