The secondary electrons are first collected by attracting them towards an electrically biased grid at about + 400 V, and then further accelerated towards a phosphor or scintillator positively biased to about + 2, 000 V. The accelerated secondary electrons are now sufficiently energetic to cause the scintillator to emit flashes of light ( cathodoluminescence ), which are conducted to a photomultiplier outside the SEM column via a light pipe and a window in the wall of the specimen chamber.

The heavy water was viewed by approximately 9, 600 photomultiplier tubes ( PMTs ) mounted on a geodesic sphere at a radius of about.

The primary advantages to the electron microscope based technique is the ability to resolve features down to 1 nanometer, the ability to measure an entire spectrum at each point ( hyperspectral imaging ) if the photomultiplier tube is replaced with a CCD camera, and the ability to perform nanosecond-to picosecond-level time-resolved measurements if the electron beam can be " chopped " into nano-or pico-second pulses.

Single photodiode detectors and photomultiplier tubes are used with scanning monochromators, which filter the light so that only light of a single wavelength reaches the detector at one time.

There are two common photomultiplier orientations, the head-on or end-on ( transmission mode ) design, as shown above, where light enters the flat, circular top of the tube and passes the photocathode, and the side-on design ( reflection mode ), where light enters at a particular spot on the side of the tube, and impacts on an opaque photocathode.

In Geiger mode the photomultiplier gain is set so high ( using high voltage ) that a single photo-electron resulting from a single photon incident on the primary surface generates a very large current at the output circuit.

The drawback, however, is that not every photon incident on the primary surface is counted either because of less-than-perfect efficiency of the photomultiplier, or because a second photon can arrive at the photomultiplier during the " dead time " associated with a first photon and never be noticed.

Other hardware components were supplied as follows: the beam-combining mirror from REOSC at Saint Pierre du Perray ; the spherical, folding and relay mirrors from Carl Zeiss AG in Oberkochen ; the external straylight baffles from CASA in Madrid ; the modulating grid from CSEM in Neuchatel ; the mechanism control system and the thermal control electronics from Dornier Satellite Systems in Friedrichshafen ; optical filters, the experiment structures and the attitude and orbit control system from Matra Marconi Space in Velizy ; instrument switching mechanisms from Oerlikon-Contraves in Zurich ; the image dissector tube and photomultiplier detectors assembled by the Dutch Space Research Organisation, SRON in The Netherlands ; the refocusing assembly mechanism designed by TNO-TPD in Delft ; the electrical power subsystem from British Aerospace in Bristol ; the structure and reaction control system from Daimler-Benz Aerospace in Bremen ; the solar arrays and thermal control system from Fokker Space System in Leiden ; the data handling and telecommunications system from Saab Ericsson Space in Gothenburg ; and the apogee boost motor from SEP in France.

directed at the photomultiplier tube's photocathode which is connected to the negative of a high voltage source.

The fiber optic bundle was embedded in a fiber optic plate to be terminated at a relay optic device that transmitted fiber end signal on into six photodiodes and 18 photomultiplier tubes that were arrayed across a thick aluminum tool plate, with sensor weight balanced vs the telescope on opposite side.

If a single detector, such as a photomultiplier tube or photodiode is used, the grating can be scanned stepwise so that the detector can measure the light intensity at each wavelength ( which will correspond to each " step ").

Each detector had a central scintillation spectrometer crystal of NaI ( Tl ) 12 in ( 303 mm ) in diameter, by 4 in ( 102 mm ) thick, optically coupled at the rear to a 3 in ( 76. 2 mm ) thick CsI ( Na ) crystal of similar diameter, viewed by seven photomultiplier tubes, operated as a phoswich: i. e., particle and gamma-ray events from the rear produced slow-rise time (~ 1 μs ) pulses, which could be electronically distinguished from pure NaI events from the front, which produced faster (~ 0. 25 μs ) pulses.

AMANDA consists of optical modules, each containing one photomultiplier tube, sunk in Antarctic ice cap at a depth of about 1500 to 1900 metres.

Another detector type for Cherenkov light was AIROBICC ( AIRshower Observation By angle Integrating Cherenkov Counters ) with one large photomultiplier looking at the sky above it.

In 1956, Robert Hanbury Brown and Richard Q. Twiss published A test of a new type of stellar interferometer on Sirius, in which two photomultiplier tubes ( PMTs ), separated by about 6 meters, were aimed at the star Sirius.

A neutrino beam consisting primarily of muon neutrinos is directed at a detector filled with 800 tons of mineral oil and lined with 1, 280 photomultiplier tubes.

The first documented photomultiplier demonstration dates to the early 1934 accomplishments of an RCA group based in Harrison, NJ.

By October 1935, Vladimir Zworykin, George Ashmun Morton, and Louis Malter of RCA in Camden, NJ submitted their manuscript describing the first comprehensive experimental and theoretical analysis of a multiple dynode tube — the device later called a photomultiplier — to Proc.

Following a corporate break-up in the late 1980s involving the acquisition of RCA by General Electric and disposition of the divisions of RCA to numerous third-parties, RCA's photomultiplier business became an independent company.

Burle Industries, as a successor to the RCA Corporation, carried the RCA photomultiplier business forward after 1986, based in the Lancaster, Pennsylvania facility.

Seven years later, in late 1935, Zworykin's photograph appeared on the cover of the trade journal Electronics, holding an early RCA photomultiplier prototype.

The coincidence circuit assures that genuine light pulses, which reach both photomultiplier tubes, are counted, while spurious pulses ( due to line noise, for example ), which would only affect one of the tubes, are ignored.

As the gamma ray passed through a cylinder of doped sodium iodide, it would emit light that would be detected by a photomultiplier tube.

After fifty years, during which solid-state electronic components have largely displaced the vacuum tube, the photomultiplier remains a unique and important optoelectronic component.

A dynode is one of a series of electrodes within a photomultiplier tube.

A spectrum within a certain wavelength range can be recorded simultaneously by using a two-dimensional position-sensitive detector such as a microchannel photomultiplier plate or an X-ray sensitive CCD chip ( film plates are also possible to use ).

When a single photon is sent through an interferometer, it passes through both paths, interfering with itself, as waves do, yet is detected by a photomultiplier or other sensitive detector only once.

The detection of these photons has been made possible ( and easier ) by the development of more sensitive photomultiplier tubes and associated electronic equipment.

UV-visible spectroscopy of microscopic samples is done by integrating an optical microscope with UV-visible optics, white light sources, a monochromator, and a sensitive detector such as a charge-coupled device ( CCD ) or photomultiplier tube ( PMT ).

Behind this grid system, an image dissector tube ( photomultiplier type detector ) with a sensitive field of view of about 38 arc-sec diameter converted the modulated light into a sequence of photon counts ( with a sampling frequency of 1200 Hz ) from which the phase of the entire pulse train from a star could be derived.

A sensitive photomultiplier tube ( PMT ) measures the light from the crystal, and the output signal is fed to an electronic amplifier and other electronic equipment to count and possibly quantify the amplitude of the signals produced by the photomultiplier.

In subsequent years other products were added, such as cathode ray tubes, photomultiplier tubes, motion-sensing light control switches, and closed-circuit television systems.

He was an active innovator in instrumentation, being involved in new techniques such as the astronomical use of photomultiplier tubes and television techniques, and electronically controlled telescope drives.

The detectors with the lowest energy threshold were the atmospheric Cherenkov telescopes with " cameras " of photomultiplier tubes.

The fluorescence signal is captured by a photomultiplier a known distance downstream of the de Laval nozzle.

In a photomultiplier tube, every photon striking the photocathode initiates an avalanche of electrons that produces a detectable current pulse.

This light then passed through an exit slit into photomultiplier tubes that produced pulses or " sprays " of electrons.

Currently available scanners typically use charge-coupled device ( CCD ) or contact image sensor ( CIS ) as the image sensor, whereas older drum scanners use a photomultiplier tube as the image sensor.

The amplified electrical signal output by the photomultiplier is displayed as a two-dimensional intensity distribution that can be viewed and photographed on an analogue video display, or subjected to analog-to-digital conversion and displayed and saved as a digital image.

Mounted on the superstructure are 11, 146 photomultiplier tubes ( PMT ) in diameter that face the ID and 1, 885 PMTs that face the OD.

The detector, named KamiokaNDE for Kamioka Nucleon Decay Experiment, was a tank in height and in width, containing 3, 048 metric tons ( 3, 000 tons ) of pure water and about 1, 000 photomultiplier tubes ( PMTs ) attached to its inner surface.

On November 12, 2001, about 6, 600 of the photomultiplier tubes ( costing about $ 3000 each ) in the Super-Kamiokande detector imploded, apparently in a chain reaction or cascade failure, as the shock wave from the concussion of each imploding tube cracked its neighbours.

Although wide bandwidth sources typically suffer from low spectral power per unit frequency, the photomultiplier tube offers high gain ( about ) amplification of photon shot noise, making it advantageous over other lower gain noise sources.

The scanner had a single photomultiplier detector, and operated on the Translate / Rotate principle.

This machine had 30 photomultiplier tubes as detectors and completed a scan in only 9 translate / rotate cycles, much faster than the EMI-scanner.

After passing a pinhole, the light intensity is detected by a photodetection device ( usually a photomultiplier tube ( PMT ) or avalanche photodiode ), transforming the light signal into an electrical one that is recorded by a computer.

From there, a fiber optic will transfer the light out of the microscope where it will be separated by a monochromator and then detected with a photomultiplier tube.

In wavelength dispersive analysis, the single-wavelength radiation produced by the monochromator is passed into a photomultiplier, a detector similar to a Geiger counter, which counts individual photons as they pass through.

The film was developed on-orbit, and then scanned by a photomultiplier for transmission to Earth.

Elements of photomultiplier technology, when integrated differently, are the basis of night vision devices.

The invention of the photomultiplier is predicated upon two prior achievements, the discoveries of the photoelectric effect and the secondary emission ( i. e., the ability of electrons in a vacuum tube to cause the emission of additional electrons by striking an electrode ).

The ingredients for inventing the photomultiplier were coming together during the 1920s as the pace of vacuum tube technologies accelerated.