Image Intensifier/CCD option for fiber readout

S. Manly (Rochester), R. Ransome (Rutgers)

Minerva collaboration meeting, FNAL, June 2003

Thanks to C.Walters, E.Kearns, M.Sakuda from K2K, B.Moore from Hamamatsu

Plots acquired from K2K papers (hep-ex/0206041, 0004024), Roper Scientific technical note #11, Hamamatsu Image Intensifier catalog, Roger Rusak/Ken Heller’s talk (ANL, April 2003)

Used successfully in past for fiber trackers in HEP

K2K - 275K fibers

CHORUS - 1.2 million fibers

UA2 - 60K fibers

DONUT - 500K fibers

From Roper Scientific

Image Intensifiers/CCDs

Hamamatsu

Gain is on the order of 103 to 104 per MCP stage

Microchannel plate

From Roper Scientific

Image Intensifiers/CCDs

Many choices of configuration:

• Photocathode (size and material)

• number of MCP stages

• phosphor

• optical or fiberoptic taper to CCD (if needed)

• CCD vs. EB-CCD

Simplest option, do as K2K did:

2 stage (1electrostatic, 1 MCP)

100 mm diameter photocathode

pack ~11,500 0.7 mm fibers/unit

P20 phosphor (slow, 1 ms decay)

(tracking only)

Fiber packing and calibration: K2K

~11,500 fibers per unit

100 mm diam units, 0.7 mm fibers

K2K pixel readout

Discussions (Ransome) with Kearns,Walters, Sakuda, Moore

K2K happy with their system

IIT used by K2K no longer available

Camera used by K2K no longer available

Simplest option not available

Discussions (Ransome) with Kearns,Walters, Sakuda, Moore

They suggest we consider:

C8600 intensifier (2-stage MCP)

good linearity

200 ns gate

can come with P47 fast decay phosphor

18 mm dia photocathode

~$28K per unit

Phosphor choices

Hamamatsu

Suggested camera

= C7190 Electron Bombardment CCD camera

Has gain, good linearity

expensive ($59K/unit)

C7190 & C8600 combination

has ~108 gain

may be linear enough to get some pulse height info

fast enough to get some timing info (O(200 ns) gating and decay time with P47 phosphor)

has small photocathode diameter (will want demagnification stage in front)

costs $90K per unit

C7190 & C8600 combination

go to cheaper camera? No gain, means need three stage IIT probably (unless 106 is enough)

How much demagnification can we get? How big are our fibers (.5 mm vs. 1.2 mm is a big difference)?

Current working cost estimate for 20K channels is $300K

Transition from last stage to CCD: lens vs. fiber coupling

Fiber coupling is advised for low light uses

Need to look at cost/benefit for our system

Use such a taper for the front of our system?

In the works ...

Sakuda says Hamamatsu is developing an IIT with the luminescent plate replaced by a CCD or a multi-pixel avalanche photodiode (MPAD) … called HPD

Expensive and under development.

Understand post CCD readout - digitized signal comes from the camera, full readout at 4-7 Hz

Phosphor tradeoffs?

MCP lifetime (CHORUS replaced ~3% MCP’s every 6 months)

Camera vs. 3-stage IIT tradeoff

Demagnification limitations

Still much to think about ...