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A radionuclide identification device (RID or RIID) is a small, lightweight, portable gamma-ray spectrometer used for the detection and identification of radioactive substances. [1]
This notation is used to specify electron configurations and to create the term symbol for the electron states in a multi-electron atom. When writing a term symbol, the above scheme for a single electron's orbital quantum number is applied to the total orbital angular momentum associated to an electron state.
An HID connected to a gas chromatograph (GC) has the great advantage to use helium as both the carrier gas and the ionization gas. An HID is an ion detector which uses a radioactive source, typically β-emitters, to create metastable helium species. [1] The radioactive source ionizes helium atoms by bombarding them with emissions.
If the part is leaky, helium will be able to penetrate the device. Later the device will be placed in a vacuum chamber, connected to a vacuum pump and a mass spectrometer. The tiny amount of gas that entered the device under pressure will be released in the vacuum chamber and sent to the mass spectrometer where the leak rate will be measured.
Bottom part is a piezoelectric sample stage. Right: electron micrograph of a SQUID probe and a test image of Nb/Au strips recorded with it. [1] In condensed matter physics, scanning SQUID microscopy is a technique where a superconducting quantum interference device (SQUID) is used to image surface magnetic field strength with micrometre-scale ...
The scattered gas is then detected using a mass spectrometer. By then rastering the sample, an image of the sample can be formed. The scanning helium microscope (SHeM) is a form of microscopy that uses low-energy (5–100 meV) neutral helium atoms to image the surface of a sample without any damage to the sample caused by the imaging process ...
As the helium ion beam interacts with the sample, it does not suffer from a large excitation volume, and hence provides sharp images with a large depth of field on a wide range of materials. Compared to a SEM, the secondary electron yield is quite high, allowing for imaging with currents as low as 1 femtoamp. The detectors provide information ...
The detector uses an electrical discharge in helium to generate high energy UV photons and metastable helium which ionizes all compounds except helium. [1] The ions produce an electric current, which is the signal output of the detector. The greater the concentration of the component, the more ions are produced, and the greater the current.