Scintillation is the process by which a material converts radiation into light.

The use of scintillation in inorganic salts to detect radiation dates back over a century to when it was first used in the discovery and calibration of radioactivity. Today, scintillation detectors are used in a variety of remote sensing and non-invasive applications such as medical imaging, security screening for nuclear materials, astrophysical exploration and geophysical exploration in the pursuit of new energy reserves. At the heart of such detectors is a high purity material that scintillates in response to ionizing radiation. Over the decades, dozens of different scintillator materials have become commercially available and triggered further developments through continued research.
Key Factors for an Ideal Scintillator

Key factors for an ideal scintillator:

· High light output (brightness)

· High gamma ray stopping efficiency

· Fast response

· Low cost

· Good proportionality

· Minimal afterglow
Overcoming Materials Shortcomings

Although many candidate materials possess a good combination of physical properties, no single material provides the desired combination of stopping power, light output and decay time. To overcome some of these shortcomings, advanced signal processing techniques have been used; however, existing materials and signal processing technologies are approaching their physical limits, creating new material challenges.
Demands of Next Generation Scintillation Detectors

The ever more demanding imaging and exploratory applications call for the next generation of scintillation detectors to have very high response rates, be highly sensitive to low amounts of radiation and be tunable to specific radiation types.
General Types of Scintillator Materials

There are three general types of scintillator materials:

· Organic

· Inorganic

· Gas
Organic Scintillator Materials

Properties of organic scintillator materials:

· Fast response time

· Low cost

· Ease of processing

· Poor light output

· Non-linear conversion
Inorganic Scintillator Materials

Properties of inorganic scintillator materials:

· Best light output

· Most linear conversion

· Highest sensitivity

· Slow response times
Gaseous Scintillator Materials

Properties of gaseous scintillator materials:

· Fast response time

· Low scintillation efficiency
Producing the Ideal Inorganic Scintillator

Breakthroughs in materials processing, particularly techniques in making ultra-pure materials and in fabricating unique compositions for crystal growth, are enabling the pursuit of the ideal inorganic scintillator.