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Micro-Photomultiplier
Array--NanoSciences
Corporation,
Mr.
Robert Wright, Principal Investigator,
Dr.
Charles P. Beetz, Business Official, cbeetz@nanosciences.com
DOE
Grant No. DE-FG02-02ER83523
Amount:
$750,000
Many
nuclear physics experiments supported by the DOE use photomultiplier tubes
(PMTs) for the detection of optical signals induced by nuclear particles in
detectors. PMTs are the most
sensitive light detectors available and are frequently utilized when
single-photon and excellent- timing signal detection are necessary. However,
hand-assembled PMTs are relatively
bulky, expensive vacuum tube devices that haven’t changed significantly in the
last few decades. The miniaturization of photomultipliers, from traditional
photocathode sizes of approximately 1 cm diameter down to sub-millimeter sizes,
would expand the applicability of this light detection technology for both
scientific experimentation and commercial utility.
This project will produce sealed and working prototype
micro-photomultiplier arrays (MPA). Phase
I modeled and optimized the two-dimensional MPA structure, using electric field
calculation and electron trajectory mapping software. Batch
mode semiconductor processes were developed to fabricate parts with micrometer
precision. Microdynode fabrication
was accomplished using standard semiconductor process techniques, and a
micromachined, fully pixellated dynode structure for producing a
micro-photomultiplier array was demonstrated.
Phase II will focus on improved manufacturability, improved dynode
assembly, the use of higher secondary-electron-yield coatings, photocathode
processing compatibility, adding multi-anode readout capability, and final
device packaging and testing. Forty
prototype sealed micro-photomultiplier arrays will be fabricated.