special focus workshop “towards 10 ps single soft photon detectors”
DESCRIPTION
Special Focus Workshop “Towards 10 ps single soft photon detectors” 2013 IEEE NSS/MIC/RTSD Seoul Sunday Oct 27, 2013. A very successful soft photon detector: the Photomultiplier (1934). ‘good’ quantum efficiency rather fast low noise @ high gain: very sensitive - PowerPoint PPT PresentationTRANSCRIPT
Special Focus Workshop
“Towards 10 ps single soft photon detectors”
2013 IEEE NSS/MIC/RTSD SeoulSunday Oct 27, 2013
A very successful soft photon detector: the Photomultiplier (1934)
- ‘good’ quantum efficiency- rather fast- low noise @ high gain: very sensitive- little dark current, no bias current- radiation hard- quite linear
- voluminous & heavy- no position resolution- expensive- quite radioactive- can’t stand B fields
Amplification by multiplication: low noise!
Photo DiodeAvalanche Photo Diode APDSingle Photon Avalanche Diode SPADGeigerMode Avalanche Photodiode GM-APDDigital Photo Counters
The Silicon PhotoMultiplier: SiPM
Si-PMs are now in the focus:
Efficiency: potentially 100 %but: pixelizing reduces efficiency (borders)
Flat, thin, light, cheapCapable to stand strong B-fieldNoise, afterpulsing, recovery timeBest possible time resolution……?
MCP (invacuum)
John Vallerga: TimePix + MCPs
We do not know how to make MEMS made MCPs.Problems: aspect ratio of holes, ion back flow, acceptance
Use a MicroChannelPlate MCP?
Quantum Limited Imaging Detectors, RIT 2009, John Vallerga, [email protected]
The transmission dynode: ultra thin (20 - 100 nm) layers
diamondSiNitride (Si3N4) Si doped (SiRichNitride, SRN)CsIdoped SiO2
In vacuum: no gaseous detector………..
- ultra fast (single electron) detector: σ = 10 ps- E-force much larger than Lorenz force: operates in B-field- radiation hard- low mass
In vacuum: no gaseous detector………..
Classical Photo Cathode: Quantum Efficiency (QE) ~ 40 % at max
Can this be largely improved?
Towards we ain’t there yet10 ps not quite an arbitrary goalsingle the ultimate sensitivitysoft ~ 1 eV: there are other photons (like 511 keV)photon a very fundamental particledetectors that is where we are here for
Have a good exchange of information!
At the end:
Provoking speakers:Paul LecoqGary VarnerJohn Smedley
bringing forward ‘aggressive’ thesis’ like:
‘with Si-PMs 10 ps time resolution may be feasible,but at the cost of a lot of noise’
‘Scintillators are too slow for applications in 10 ps detectors Contrarily, Cherenkov radiation becomes more important’
‘There is no fundamental limit for the QE of photo cathodes’