NaI(Tl) Scintillator
Encapsulated NaI(Tl) Scintillator for Gamma-Ray Detection
General Encapsulated NaI(Tl) Scintillator is a hermetically sealed thallium-doped sodium iodide scintillator used for gamma-ray detection, counting and spectroscopy. NaI(Tl) offers high light output, good energy resolution and strong compatibility with photomultiplier tubes.
Because NaI(Tl) is hygroscopic, reliable encapsulation is essential. ATR Crystal supplies cylindrical NaI(Tl) crystals in aluminum or stainless steel housings with K9 glass, quartz or sapphire optical windows. Face-entry and side-entry radiation configurations, flanges, mounting features and other mechanical modifications can be reviewed.
Standard cylindrical sizes are available, and custom sizes can be reviewed up to 150 mm diameter x 400 mm height according to crystal growth, polishing, encapsulation and performance requirements.
Design Options
| Design Item | Available Option | Notes |
|---|---|---|
| Metal container | Aluminum or stainless steel | Selected according to weight, mechanical strength, environment and mounting requirement. |
| Optical window | K9 glass, quartz or sapphire | Window choice depends on optical coupling, mechanical strength and environmental requirement. |
| Geometry | Cylindrical encapsulated NaI(Tl) | Common for PMT-coupled gamma-ray detection modules. |
| Custom mechanical features | Special flanges, mounting fixtures or other modifications | Provide drawing for review. |
| Maximum crystal size | Dia. 150 mm x height 400 mm | Subject to specification, encapsulation and performance review. |
When to Choose Encapsulated NaI(Tl) Instead of Bare NaI(Tl)
NaI(Tl) crystal is highly hygroscopic, so a sealed scintillator package is normally recommended for real detector use. Encapsulation protects the crystal from moisture and allows the optical window, reflector and mechanical housing to be matched to the readout design.
If your request mentions a pure NaI crystal scintillator, please confirm whether a hermetically sealed NaI(Tl) scintillator is acceptable. In most gamma spectroscopy and radiation monitoring instruments, encapsulated NaI(Tl) is more reliable than a bare crystal unless the user has immediate dry-box integration capability. For material-level background, read the NaI(Tl) crystal selection guide.
Features of Encapsulated NaI(Tl)
- PMT-compatible emissionThe emission spectrum of NaI(Tl) is well matched with many photomultiplier tubes.
- High light outputNaI(Tl) is widely used where high scintillation light yield is required.
- Good energy resolutionStandard encapsulated models list <=8.0% at 662 keV or better, depending on size and configuration.
- Hermetic protectionAluminum or stainless steel housings protect the hygroscopic NaI(Tl) crystal.
- Custom window choiceK9 glass, quartz or sapphire windows can be reviewed according to detector design.
- Custom detector integrationNaI(Tl) crystals can be integrated with PMTs, housings and detector assemblies.
Typical Specification
| Model | Crystal Size | Encapsulation | Energy Resolution, Cs-137 |
|---|---|---|---|
| NaI-D25H25 | Dia. 25.4 x 25.4 mm | Aluminum housing with K9 glass window | <=8.0% at 662 keV or better |
| NaI-D25H40 | Dia. 25.4 x 40.0 mm | Aluminum housing with K9 glass window | <=8.0% at 662 keV or better |
| NaI-D40H40 | Dia. 40.0 x 40.0 mm | Aluminum housing with K9 glass window | <=8.0% at 662 keV or better |
| NaI-D50H50 | Dia. 50.8 x 50.8 mm | Aluminum housing with K9 glass window | <=8.0% at 662 keV or better |
| NaI-D63H63 | Dia. 63.5 x 63.5 mm | Aluminum housing with K9 glass window | <=8.0% at 662 keV or better |
| NaI-D76H76 | Dia. 76.2 x 76.2 mm | Aluminum housing with K9 glass window | <=8.0% at 662 keV or better |
| NaI-D127H127 | Dia. 127 x 127 mm | Aluminum housing with K9 glass window | <=8.0% at 662 keV or better |
Note: other sizes or specifications can be customized according to your requirements.
General NaI(Tl) vs. Related Encapsulated Scintillators
| Product | Best Fit | Main Advantage | Design Notes |
|---|---|---|---|
| General encapsulated NaI(Tl) | Standard cylindrical gamma detector crystals | High light output and mature PMT readout | Requires hermetic encapsulation. |
| Square Type NaI(Tl) | Rectangular detector arrays and close-packed layouts | Better packing geometry for square/cuboid detectors | Housing and window position should match readout plan. |
| X-Ray Type NaI(Tl) | Low-energy X-ray detection | Thin crystal/window design for low-energy photons | Window material and thickness are critical. |
| End Well NaI(Tl) | Sample counting with well geometry | High counting efficiency around small samples | Well size and sample geometry must be specified. |
| LaBr3(Ce) Scintillator | High-resolution gamma spectroscopy | Better energy resolution and fast timing | Higher cost and intrinsic La-138 background should be considered. |
NaI(Tl) RFQ Checklist
| RFQ Item | Information to Provide |
|---|---|
| Application | Gamma spectroscopy, survey meter, counting system, environmental monitoring or detector module. |
| Crystal size | Diameter, height, tolerance and preferred standard model if applicable. |
| Encapsulation | Aluminum or stainless housing, K9/quartz/sapphire window, flange and mounting features. |
| Performance target | Energy resolution at Cs-137 662 keV, light output, uniformity and inspection requirement. |
| Readout | PMT, SiPM, photodiode, optical coupling, cable and electronics interface. |
| Order information | Quantity, packaging, inspection report and delivery schedule. |
