What is sodium iodide detectors?
A 2×2 inch sodium iodide (NaI) detector will allow the user to identify the presence of Cs137 at < 1 urem/hr/sec. The 3×3 inch NaI detector can identify Cs137 at 500 nrem/hr/sec. This is why BNC’s SAM III generation and SAM 940 are designed to easily hold large detectors and operate them with one hand.
What does a sodium iodide crystal do?
Sodium Iodide (Tl) – NaI(Tl) – is a well established and the most extensively used scintillator. It is used for detecting gamma rays of low and intermediate energies. It has a high level of optical output and relatively inexpensive. It is available in both single crystal and polycrystalline formats.
What method of detecting radiation uses sodium iodide crystals containing small amount of thallium iodide?
8.2 Scintillation Detectors. A scintillation detector contains a scintillator crystal optically coupled to a photomultiplier tube (PMT). The most common type of scintillator crystal consists of sodium iodide (i.e., NaI) activated with a small amount of thallium (i.e., NaI(Tl) detector).
Why is thallium used in NaI detector?
The doping of the NaI crystal with thallium improves the scintillation efficiency by improving the light emission due to the improved recombination by light emission of electrons and holes at the dopant site.
How do sodium iodide detectors work?
The thallium-activated sodium iodide detector, or NaI(Tl) detector, responds to the gamma ray by producing a small flash of light, or a scintillation. The scintillation occurs when scintillator electrons, excited by the energy of the photon, return to their ground state.
How does sodium iodide detector work?
How do scintillation crystals work?
Scintillators are a group of materials that luminesce when exposed to ionizing radiation. In layman’s terms that means these materials emit light when they absorb particles or electromagnetic waves that create “free” electrons in the material.
What are the two most widely used scintillation phosphor?
Inorganic Scintillation Phosphors They include lithium iodide (LiI), sodium iodide (NaI), cesium iodide (CsI), and zinc sulfide (ZnS). The most widely used scintillation material is NaI(Tl) (thallium-doped sodium iodide).
How does a sodium iodide detector work?
How does a scintillator crystal work?
A scintillator is a material that exhibits scintillation – the property of luminescence (sparkles of light), when excited by ionising radiation. After absorbing a gamma ray, a scintillation crystal emits a pulse of light, usually in the visible spectrum.
What kind of detector is sodium iodide used for?
This detector, in which Sodium Iodide (NaI) was used, was used for radiation measurements. The infrared optical crystal is a principal part of the technology on which infrared gas analyzers are based. Gas analyzers are the company’s prime products. But on the other hand, the growing of large-sized crystals has also become very successful.
What causes scintillation in sodium iodide ( NaI ) crystal?
In 1948, it was reported that there was a large scintillation phenomenon caused by adding a trace quantity of Thallium (Tl) into a crystal of Sodium Iodide (NaI). HORIBA started manufacturing and development of the NaI (Tl) crystal shortly after NaI (Tl) was discovered.
What kind of detector is used for scintillation?
In the following year, development of the scintillation detector began. This detector, in which Sodium Iodide (NaI) was used, was used for radiation measurements. The infrared optical crystal is a principal part of the technology on which infrared gas analyzers are based.
Why does sodium iodide absorb gamma rays well?
The high atomic number of the iodine component (53) ensures that large crystals of sodium iodide will fully absorb the energy of a large fraction of all incident gamma rays.