Designing a scintillation detector to ensure optimal performance for a specific measurement can be a daunting task. There are numerous important variables that must be considered. The ASI scientific and engineering staff are experts in detector design and we are prepared to provide guidance to help you make these design decisions. Don’t hesitate to call or send an email to us at any time. To get started, let’s look at a few basic gamma detector design issues.
This discussion will help the customer prepare responses to basic design considerations that need to be resolved in order to build a detector that will meet your experimental requirements. Once this information is obtained contact us and we will provide the support required to complete the detector design process. The important components of a detector are:
- Crystal material
- Reflector
- Interface materials
- Light pipe
- Crystal housing
- Hermetic seal and light seal
- Photosensitive device selection
- Voltage divider and preamp.
We need the customer to provide valuable information to determine the appropriate crystal material, crystal housing material and selection of the photosensitive device. The design of the remaining components will be determined by the ASI design team.
To get started on a detector design, these basic questions must be considered:
- What is the gamma-ray energy of interest? Are there multiple regions of interest?
- How critical is it to obtain the best spectroscopic data? Is it only important to detect the presence of gamma radiation?
- What is the expected count rate?
- What is the desired counting time?
- Is the size or shape of the detector constrained?
- Will the detector be shielded?
- Is the intrinsic background of the detector package important?
- What are the environmental conditions where the detector will be used?
- Will the detector experience thermal shock?
- Will the detector be exposed to mechanical shock and vibration?
- Is there an existing detector that is being used to provide measurements?
Once this information is gathered, or as much as possible, please contact us to help complete the detector design. ASI will work with the customer to arrive at an acceptable design. Then, once an order is placed our design engineer will create a formal sales drawing for the customer to review and sign off before our manufacturing process is initiated.
Additional technical information about scintillator materials and properties is provided below.
ASI Request for Quote and Detector Design Form
For an extensive write up on the scintillator technology consider reading the Book Chapter on Scintillators.
ASI Scintillation Materials Data Sheet
Meeting the needs of the numerous applications we serve requires diverse capabilities. ASI offers many different scintillation detector materials to satisfy these requirements. Here’s a table listing what we offer.
Scintillator General Properties and Typical Applications
| Scintillator Material | Advantages | Examples of Applications |
| NaI(Tl)1 | Good light yield, best cost | General counting, x-ray counting, dose calibration, commercial gauges, health physics, Compton Suppression, medical imaging, geophysical exploration, homeland security, dark matter experiments |
| CsI(Na)1 | Good light yield, rugged | Geophysical exploration, general counting |
| CsI(Tl)1 | Non-hygroscopic, rugged | Photodiodes, high energy physics, phoswiches |
| CsI(pure)1 | Fast light output | Calorimetry |
| BGO | High density | Geophysical exploration, general counting, Compton Suppression, geophysical exploration |
| CaF2(Eu) | Non-hygroscopic, good light yield | β detectors, special α – β phoswiches |
| CeBr3 | Very good light yield, fast light output | Geophysical exploration, hand held meters |
| LaCl3(Ce) | Very good light yield, fast light output | Geophysical exploration, hand held meters |
| 6LiI(Eu) | Good light yield, good neutron cross section | Thermal neutron detection, gamma spectroscopy |
| 6Li-glass | Good neutron cross section, non-hygroscopic | Thermal neutron detection |
| CdWO4 | High density, low afterglow | Photodiodes, high count rate x-ray scanners |
| BaF2 | Very fast light output | Fast timing, nuclear physics research |
| LYSO | High density, fast light output | General counting, commercial gauges |
| SrI2(Eu) | Very Good light yield | Hand held meters |
| Plastic | Fast light output, low density, good light yield | Screening monitors, particle detection, β monitors |
| Liquid | Fast light output, low density, good light yield | Nuclear physics research |
1Materials currently grown at ASI.
2Materials in development at ASI.
Properties of Scintillation Detector Materials
Please note, you may need to rotate your mobile device to view the entire table below:
| Scintillator Material |
Density [g/cm3] |
Hygroscopic | Emission Wavelength [Max.] |
Light Yield3 [NaI(Tl)=100] [%] |
Principal Decay Constant [µsec]4 |
Index of Refraction5 n |
| NaI(Tl)1 | 3.67 | Yes | 415 | 100 | 0.23 | 1.85 |
| CsI(Na)1 | 4.51 | Slightly | 420 | 85 | 0.63 | 1.84 |
| CsI(Tl)1 | 4.51 | No | 550 | 456 | 0.68 | 1.80 |
| CsI(pure)1 | 4.51 | No | 315 | 4-6 | 0.016 | 1.95 |
| BGO | 7.133 | No | 480 | 20 | 0.3 | 2.15 |
| CaF2(Eu) | 3.18 | No | 435 | 50 | 0.9 | 1.44 |
| CeBr3 | 5.07 | Yes | 380 | 155 | 0.019 | 2.09 |
| LaCl3(Ce) | 3.79 | Yes | 330/352 | 120 | 0.070/0.0003 | 1.81 |
| 6LiI(Eu)1 | 4.08 | Yes | 470 | 35 | 1.4 | 1.96 |
| 6Li-glass | 2.6 | No | 390-430 | 4-6 | 0.060 | 1.56 |
| CdWO4 | 7.90 | No | 480 | 30-50 | 20 | 2.20 |
| BaF2 | 4.89 | Yes | 220/320 | 3/16 | 0.62/0.0006 | 1.47 |
| LYSO | 7.3 | No | 397 | 75 | .00041 | 1.82 |
| SrI2(Eu) | 4.59 | Yes | ~430 | ~210 | ~0.003 | 1.85 |
| Plastics | 1.02 | No | 370 | 25-30 | 0.00141 | 1.58 |
| Liquids | 1.00 | No | 425 | 35-45 | 3.2 | 1.505 |
1Materials currently grown at ASI.
2 Materials currently in development at ASI.
3Light Yield: when coupled to a PMT with a Bialkilai photocathode at room temperature.
4At room temperature.
5At the maximum wavelength of emission.
6Best suited to be used with a photodiode due to wavelength mismatch with standard PMT.
Also, please note that ASI offers different radiopurity grades of material. Our cleanest radiopurity NaI(Tl) material called WIMPScint (link to WIMPScint data sheet) is used in several Dark Matter experiments around the world. Refer to our PDF data sheet and don’t hesitate to contact us for more details.
For more information regarding material properties please contact Alpha Spectra, Inc. Our design team will help you design a custom detector configuration to meet the needs of your measurement application.