1. 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)

2. Used successfully in past for fiber trackers in HEP K2K - 275K fibers CHORUS - 1.2 million fibers UA2 - 60K fibers DONUT - 500K fibers

3. From Roper Scientific Image Intensifiers/CCDs Hamamatsu Gain is on the order of 10 3 to 10 4 per MCP stage Microchannel plate

4. 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

5. 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)

6. Fiber packing and calibration : K2K ~11,500 fibers per unit 100 mm diam units, 0.7 mm fibers

7. K2K pixel readout

8. 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

9. 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

10. Phosphor choices Hamamatsu

11. Suggested camera = C7190 Electron Bombardment CCD camera Has gain, good linearity expensive ($59K/unit)

12. C7190 & C8600 combination  has ~10 8 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

13. C7190 & C8600 combination  go to cheaper camera? No gain, means need three stage IIT probably (unless 10 6 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

14. 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?

15. 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.

16. 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...