[Triumf-seminars] TRIUMF Technical Seminar today at 11:00

[TRIUMF Seminars]

Date/Time: Tue 2013-07-23 at 11:00

Location:  Auditorium          

Speaker:   Harry Van Der Graaf (NIKHEF)

Title:     Ultrafast dynode electron multiplying detectors

Abstract: We propose to place a stack of ultra thin transmission dynodes on top of a pixel chip, in vacuum. A single electron arriving at the first dynode will cause an electron avalanche on the pixel input pad. Due to the small source capacitance, a gain of 30 k of the dynode stack is sufficient to create a digital signal. The rise time of this signal could be ~ 2 ps. This single-electron sensitive device has therefore an excellent time resolution, and, due to the granularity of the pixel chip, a good 2D position resolution. When capped with a classical window+photocathode, a new photomultiplier
is created. This Timed Photon Counter 'Tipsy' is single soft photon sensitive, has 2D position resolution defined by the granularity of the pixel chip, and a potential time resolution of ~ 2 ps per photon. Thanks to the granularity of the pixel chip, a high rate of multiple photon events results in an acceptable pixel occupancy; When capped with an electron emission membrane 'e-brane', the electron detector turns into Trixy: a tracker for charged particles (MIPs). The essential property of this membrane is the emission, with a high probability, of at least one electron after the passage of a MIP, at the crossing point of the MIPs' track and the membrane. We intend to develop a high-yield e-brane by applying a low escape-potential surface, such as a bi-alkali photocathode, possibly in combination with a Cherenkov radiator as window.


Stimulants available 15 minutes before the talk.

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