NEXT GENERATION PHOTOMULTIPLIERS Jon Howorth Photek Ltd
ORIGINS OF PHOTO-TUBES • Photo-Electric Effect Hertz 1887 • Theoretical Explanation Albert Einstein 1905 • All Electronic TV System proposed by Professor Rosing of St Petersburg 1907 • Photo-diodes enable the “talkies” 1934
DISEMINATION from St Petersburg • Zworykin went to work for RCA • Schoenberg went to HMV in 1914, became head of Research. • Schoenberg hired Lubszinski in 1934 • Both had almost identical TV cameras by 1934 • Another colleague, Serge Aisenstein had contact with Marconi, and fled to Poland. Later ran EEV in UK
The first Photomultipliers ; Generation ZERO • S-1 photocathode; • 5-stage mesh dynode • 50,000 gain • Build by the later famous Alfred Sommer for “Fernseh” in Berlin from 1934 • Shown at the Berlin Radio Show in 1936 as a tele-cine projection system
Sommer—Continued ; Generation ONE • 1937 refugee status in UK • Employed by Baird on tele-cine • During the war, build hundreds of thousands of photo-cells for proximity fuses • After the war, Sommer went to HMV, and worked with Lubszinski on TV tubes and developed the first High gain, low noise photomultipliers.
Sommer—Continued--twice • In 1953, Sommer emigrated to RCA • HMV started to decline, RCA along with EEV dominated TV Camera tubes for the next 20 years • But RCA sold technology to Hamamatsu in 1969 • Sommer went to Hamamatsu as a consultant—as his last job.
MCP Technology----Generation 2 • MCPs were invented independently and simultaneously on both sides of the Atlantic. • Goodrich et al at Bendix Research Labs • John Adams, Derek Washington and Brian Manley at Mullard Research Labs. • Both sides had Gen 2 night vision tubes by 1970. • Both sides used different glass and etches. • Ensuing patent war rumbled on for 30 years.
Why is Diamond so Fast? say 500 A Then the field is 105 V/mm
Diamond at Photek • Collaboration with Bristol Uni; STFC (Rutherford); AWE; Leicester Uni & Photek started 2009 • Gain from Bristol material is as good/ better than US • Operational life testing shows good gain stability and little cathode damage • STFC micro machined parts to 50µm being made • Plans for 20µm for next step
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