this mass threshold was derived from the detector calibration and an assumed impact velocity of Af.

If a detector was placed at a distance of 1 m, the ion flight times would be X and Y ns.

The crystal detector was developed into a practical device for wireless telegraphy by Greenleaf Whittier Pickard, who invented a silicon crystal detector in 1903 and received a patent for it on November 20, 1906.

This troublesome device was superseded by thermionic diodes by the 1920s, but after high purity semiconductor materials became available, the crystal detector returned to dominant use with the advent of inexpensive fixed-germanium diodes in the 1950s.

In the SEM image of an ant shown at right, the image was constructed from signals produced by a secondary electron detector, the normal or conventional imaging mode in most SEMs.

After the development of his electron capture detector, in the late 1960s, Lovelock was the first to detect the widespread presence of CFCs in the atmosphere.

His invention, known as the Polish mine detector, was used by the Allies alongside mechanical methods, to clear the German mine fields during the Second Battle of El Alamein when 500 units were shipped to Field Marshal Montgomery's Eighth Army.

According to the 9 / 11 Commission Report, Moqed set off the metal detector at the airport and was screened with a hand-wand.

This was made possible by the development of a secondary-electron detector

The detector was designed to detect solar neutrinos through their interactions with a large tank of heavy water.

The detector was turned on in May 1999, and was turned off on 28 November 2006.

The detector cavity outside the vessel was filled with normal water to provide both buoyancy for the vessel and radioactive shielding.

The SNO detector would have been capable of detecting a supernova within our galaxy if one had occurred while the detector was online.

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.

The detector was upgraded, starting in 1985, to allow it to observe solar neutrinos.

As a result, the detector ( KamiokaNDE-II ) had become sensitive enough to detect neutrinos from SN 1987A, a supernova which was observed in the Large Magellanic Cloud in February 1987, and to observe solar neutrinos in 1988.

The work was completed in June 2006, whereupon the detector was renamed Super-Kamiokande-III.

However, on March 26, 1983, the first test, known as the Cabra event, was performed in an underground shaft and resulted in marginally positive readings that could be dismissed as being caused by a faulty detector.

Since a nuclear explosion was used as the power source, the detector was destroyed during the experiment and the results therefore could not be confirmed.

Because the primary mirror focuses light to a common point in front of its own reflecting surface almost all reflecting telescope designs have a secondary mirror, film holder, or detector near that focal point partially obstructing the light from reaching the primary mirror.

A neutrino detector was partially constructed in the 1990s called Project DUMAND.

In 1932, soon after the prediction of positrons by Paul Dirac, Carl D. Anderson found that cosmic-ray collisions produced these particles in a cloud chamber — a particle detector in which moving electrons ( or positrons ) leave behind trails as they move through the gas.

The radiation then passes through a monochromator in order to separate the element-specific radiation from any other radiation emitted by the radiation source, which is finally measured by a detector.

Various refinements were made to the instrument, including the use of a so-called position-sensitive ( PoS ) detector by Alfred Cerezo, Terence Godfrey, and George D. W. Smith at Oxford University in 1988.

The measuring function is completed by the detector, transducer and transmitter.

* Dose profile, taken by a radiation detector in order to characterise the radiation beams from medical linear accelerators

The appearance of interference built up from individual photons could seemingly be explained by assuming that a single photon has its own associated wavefront that passes through both slits, and that the single photon will show up on the detector screen according to the net probability values resulting from the co-incidence of the two probability waves coming by way of the two slits.

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.

Fluorescence in several wavelengths can be detected by an array detector, to detect compounds from HPLC flow.

To separate and analyze them, the fluorescent radiation is passed through an Emission monochromator, and observed selectively by a detector.

A prior separation stage is necessary and the additives are first separated by high liquid chromatography ( HPLC ) and then determined on-line using a UV and / or visible detector.

Unambiguous detection of individual gravitons, though not prohibited by any fundamental law, is impossible with any physically reasonable detector.

The sixteen instruments, weighing 118 kg altogether, included magnetometer sensors mounted on an 11 m boom to minimize interference from the spacecraft ; a plasma instrument for detecting low energy charged particles and a plasma wave detector to study waves generated by the particles ; a high energy particle detector ; and a detector of cosmic and Jovian dust.

Serial time encoded amplified microscopy ( STEAM ) is an imaging method that provides ultrafast shutter speed and frame rate, by using optical image amplification to circumvent the fundamental trade-off between sensitivity and speed, and a single-pixel photodetector to eliminate the need for a detector array and readout time limitations The method is at least 1000 times faster than the state-of-the-art CCD and CMOS cameras.

This is somewhat compensated for by placing the detector very close to the sample reducing the loss in sensitivity due to low flux.

The germanium is processed to form a p-i-n ( positive-intrinsic-negative ) diode, and when cooled to ~ 77 K by liquid nitrogen to reduce dark current and detector noise, produces a signal which is proportional to the photon energy of the incoming radiation.

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.

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

The detector is typically a photomultiplier tube, a photodiode, a photodiode array or a charge-coupled device ( CCD ).

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.

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 ).

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.

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.

The industrial contamination monitoring detector, consisting of a scintillator and photomultiplier tube, finds wide application in the field of radioactive contamination monitoring of personnel and the environment.

Yet another example of this effect in a scientific experiment was the implosion in 2001 of several thousand fragile glass photomultiplier tubes used in the Super-Kamiokande experiment, where the shock wave caused by the failure of a single detector appears to have triggered the implosion of the other detectors in a chain reaction.

A scintillation detector or scintillation counter is obtained when a scintillator is coupled to an electronic light sensor such as a photomultiplier tube ( PMT ) or a photodiode.

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 ").

The light that is not reflected by the dichroic mirror and which has a wavelength different from that emitted and impinges on it goes through an interference filter ( F2 ) which can be adjusted to a specific wavelength, thus discriminating between different fluorophores, to ultimately impinge on a photomultiplier tube ( D3 ), this is the Side FLuorescence detector ( SFL )

For instance, chromium ( III ) might be measured using a chemiluminescence method, in an instrument that contains a photomultiplier tube ( PMT ) as the detector.

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.

* Flame photometric detector ( FPD ), which uses a photomultiplier tube to detect spectral lines of the compounds as they are burned in a flame.

The scintillation X-ray detector ( XC ) aboard Vela 5A and its twin Vela 5B consisted of two 1 mm thick NaI ( Tl ) crystals mounted on photomultiplier tubes and covered by a 0. 13 mm thick beryllium window.

* A detector consisting of 396 separate hexagonal photomultiplier detectors in the center

As a result of the illumination, the sample emits light ( it fluoresces ) and a second optical system ( emission system ) collects the emitted light, separates it from the excitation light ( using a filter or monochromator system ), and measures the signal using a light detector such as a photomultiplier tube ( PMT ).

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 ).

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.

The spectrometer consists of either a monochromator ( scanning ) or a polychromator ( non-scanning ) and a photomultiplier or CCD detector respectively.