Channel Plate Photomultipliers

TCSPC is Ulnstrated in Fig. 3a. In addition to a mode-locked laser for pnlsed excitation and a detector with high time resolntion (nsnally a micro-channel plate photomultiplier tube capable of time-resolution of 20-30 ps), the required instrumentation inclndes constant-fraction discriminators to generate electrical pnlses triggered by fluorescence photons and by the reference (the excitation pulse), a time-to-amphtude converter or other device to measnre the time lag between reference and flnorescence connts, and a multichannel scaler to accumnlate... 

In the TRPL measurements performed at 2K the excitation was made by a Ti sapphire laser system, with spectrally narrow (< 1 meV) 2 ps pulses. The emitted light was dispersed by a subtractive double-grating monochromator and detected with a multi-channel plate photomultiplier in the photon-counting mode with a time resolution of 20 ps. 

Photomultiplier, or Electron multiplier, or Micro-channel plate... 

A much better time resolution, together with space resolution, can be obtained by new imaging detectors consisting of a microchannel plate photomultiplier (MCP) in which the disk anode is replaced by a coded anode (Kemnitz, 2001). Using a Ti-sapphire laser as excitation source and the single-photon timing method of detection, the time resolution is <10 ps. The space resolution is 100 pm (250 x 250 channels). 

A common experimental arrangement for the study of molecular Rydberg states is depicted in Fig. 5.31. The output beams of two pulsed narrow-band dye lasers, pumped by the same excimer laser, are superimposed and cross the molecular beam perpendicularly. The fluorescence emitted from the intermediate level (u, J ) or from the Rydberg levels (u, 7 ) can be monitored by a photomultiplier. The ions produced by autoionization (or for levels slightly below IP by field ionization) are extracted by an electric field and are accelerated onto an ion multiplier or channel plate. This allows the detection of single ions. In order to avoid electric Stark shifts of the Rydberg levels during their excitation, the extraction field is switched on only after the end of the laser pulse. Experimental details and more infor-... 

A micro-channel plate (MCP) image intensifier can be considered as an array (typically 1,024 x 1,024) of small (about 10 pm in size) photomultiplier channels... 

Electron impact (El), or Electrospray ionization (ESI), or Matrix-assisted laser desorption ionization (MALDI) — Magnetic sector, or Time-of-flight (TOP), or Quadrupole (Q) — Photomultiplier, or Electron multiplier, or Micro-channel plate... 

The electron analyser is a spherical condenser. In its focal plane there is an extended multidetector system, consisting of two closely spaced channel plate detectors in series, which results in a high amplification (10 ) of each electron beam focused on the detector in the focal plane. All pulses are transferred to optical signals by means of a phosphor amplifier and the focal plane is continuously scanned by a photomultiplier (or TV camera). After amplification the output of the photomultiplier is fed to a computer for further processing to form the final electron core level spectra. 

Multichannel Plate. A plate consisting of parallel, microscopically small channels oriented perpendicular to the surface. The inner walls of the channels have a conductive coating. When a voltage is applied between the opposite surfaces of the plate the channels work as electron multipliers. MCPs are used in photomultiplier tubes and image intensifiers. 

A microchannel plate can also be interfaced with a scintillator and photomultiplier here, the secondary electrons exiting the plate channels first strike the scintillator for electron-to-photon conversion the photons generated in this process are subsequently converted to a measurable signal by tiie photomultiplier. 

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