By What is a Channeltron detector?
These standard channeltron detector systems are based on the extended range CEM. This device is a specially formed and treated glass tube which has the effect of multiplying a single electron at the input to a pulse of electrons at the output.
How does a Channeltron work?
Instead of a series of discrete plates, a Channeltron electron multiplier uses a high resistance semiconductor material that also has high secondary electron emissivity. Gains of a Channeltron are typically 2 X 10E7 to 2 X 10E8. Channel plate electron multipliers are commonly used on X-ray Photo electron spectrometers.
How does a CEM detector work?
It has a high surface resistance which forms a continuous dynode when potential is applied between the input and output end. The dynode emits secondary electrons and through this process makes CEM capable of detecting a particle or photon. The standard CEMs are capable of detecting over 5 million particles per second.
How does an electron multiplier work?
An electron multiplier is a vacuum-tube structure that multiplies incident charges. If an electric potential is applied between this metal plate and yet another, the emitted electrons will accelerate to the next metal plate and induce secondary emission of still more electrons.
What is a high energy dynode?
High energy dynodes (HED) are now commonly used to enhance the sensitivity of ion detectors by increasing the impact energy of input ions, which increases the number of emitted secondary particles. In quadrupole systems, HED’s are usually designed to collect only low energy ions.
What is a PMT detector?
The photomultiplier is an extremely sensitive light detector providing a current output proportional to light intensity. Photomultipliers are used to measure any process which directly or indirectly emits light. PMT is a well established technology.
What is an electron multiplier used for?
An electron multiplier is used to detect the presence of ion signals emerg- ing from the mass analyzer of a mass spectrometer. It is essentially the “eyes” of the instrument (Figure 1). The task of the electron multiplier is to detect every ion of the selected mass passed by the mass filter.
What is an electron multiplier detector?
An electron multiplier is used to detect the presence of ion signals emerg- ing from the mass analyzer of a mass spectrometer. When a charged particle (ion or electron) strikes a surface, it causes secondary electrons to be released from atoms in the surface layer.
What are the two types of photomultiplier tube?
The electron multi- pliers used for photomultiplier tubes are classified into two types: normal dis- crete dynodes consisting of multiple stages and continuous dynodes such as mi- crochannel plates.
Where are photomultipliers used?
Photomultipliers are used in research laboratories to measure the intensity and spectrum of light-emitting materials such as compound semiconductors and quantum dots. Photomultipliers are used as the detector in many spectrophotometers.
How does a quadrupole work?
A quadrupole mass analyzer consists of a set of four conducting rods arranged in parallel, with a space in the middle; the opposing pairs of rods are electrically connected to each other. The field is generated when a radio frequency (RF) voltage is applied between one pair of opposing rods within the quadrupole.
What is the purpose of electron multiplier?