LYSO Crystal — Cerium-Doped Lutetium Yttrium Orthosilicate Scintillator
What Is LYSO Crystal?
LYSO crystal — cerium-doped Lutetium Yttrium Orthosilicate — is one of the most widely adopted inorganic scintillation materials in modern radiation detection. Developed as a successor to LSO and BGO, LYSO(Ce) overcomes the intrinsic radioactive background of pure LSO by partially substituting lutetium with yttrium, while retaining all the performance advantages that make lutetium silicate scintillators the standard choice for high-throughput imaging.
The crystal grows in a monoclinic structure via the Czochralski method, producing single-crystal ingots with exceptional compositional uniformity. Atr Crystal’s LYSO(Ce) ingots reach diameters up to 90 mm and lengths of 200 mm, enabling us to supply finished pixels, polished slabs, and pre-assembled array modules from a single controlled source.
Unlike NaI(Tl), this scintillator is completely non-hygroscopic, eliminating the need for hermetic encapsulation in most deployment environments. Its 420 nm emission peak is optimally matched to the spectral sensitivity of both bialkali photomultiplier tubes (PMTs) and silicon photomultipliers (SiPMs), making LYSO(Ce) a versatile drop-in scintillator for next-generation detector systems.
Application of LYSO(Ce) Array
Positron Emission Tomography (PET & TOF-PET)
CT & X-Ray Medical Imaging
High-Energy Physics Calorimeters
Cargo & Baggage Security Inspection
- Nuclear Radiation Detection & Spectroscopy
Space Physics & Astroparticle Detectors
Well Logging & Geological Exploration
Environmental Monitoring
Advantages of LYSO(Ce) Array
Ultrafast Decay Time:At 36 ns, LYSO crystal delivers one of the fastest decay times among oxide scintillators, enabling sub-200 ps coincidence timing resolution when paired with SiPMs — a key requirement for Time-of-Flight PET.
High Density & Stopping Power:A density of 7.1 g/cm³ and high effective atomic number (Zeff ≈ 66) give LYSO crystal exceptional gamma-ray stopping power, allowing compact detector geometries without sacrificing detection efficiency.
Non-Hygroscopic Nature:Unlike NaI(Tl) and LaBr₃(Ce), LYSO(Ce) crystals do not absorb atmospheric moisture. This eliminates the cost and complexity of hermetic encapsulation, simplifying detector assembly and field deployment.
Matched Emission Wavelength:The 420 nm emission peak aligns perfectly with the peak quantum efficiency of bialkali PMT photocathodes and the photon detection efficiency of SiPMs, maximizing photoelectron yield without additional optical coupling elements.
- Superior vs. BGO for Timing:LYSO crystal surpasses BGO on energy resolution (~8% vs. ~12% at 662 keV), decay time (36 ns vs. 300 ns), and light yield — while matching BGO’s density — making it the upgrade of choice for legacy BGO-based PET systems.
Custom Geometry & Array Assembly:Atr Crystal supplies LYSO(Ce) as individual pixels, polished slabs, or fully assembled pixelated arrays with BaSO₄ or ESR reflectors. Minimum pixel size: 0.5 × 0.5 mm. Any custom geometry accepted.
Quality Control for LYSO(Ce) Array
Dimension testing
Relative light output testing
Pixel light output uniformity: ≤10%；≤20%；≤30% or on request
Energy resolution testing
- Scatter Map
Specifications of LYSO(Ce) Crystal
Basic Physical & Scintillation Properties
| Parameter | Value |
|---|---|
| Chemical Formula | Lu2(1-x)Y2xSiO5:Ce (x ≈ 0.1) |
| Crystal Structure | Monoclinic |
| Density (g/cm³) | 7.1 |
| Melting Point (°C) | ~2,050 |
| Mohs Hardness | 5.8 |
| Cleavage Plane | None |
| Hygroscopic | No |
| Light Yield (photons/MeV) | ~33,000 |
| Decay Time (ns) | 36 |
| Emission Peak Wavelength (nm) | 420 |
| Refractive Index (at 420 nm) | 1.82 |
| Energy Resolution at 662 keV (%) | ~8 |
| Radiation Hardness (rad) | >10⁵ |
| Intrinsic Background | Low (Lu-176 natural decay) |
- Available Geometries & Formats
| Format | Details |
|---|---|
| Polished Pixels / Bars | Custom dimensions; typical: 1×1×10 mm to 25×25×30 mm |
| Polished Slabs / Plates | Up to 90 mm diameter or custom rectangular |
| Pixelated 1D Arrays | 1×8, 1×16, 1×32, 1×64 (customized) |
| Pixelated 2D Arrays | 4×4, 8×8, 16×16, 32×32, 64×64 (customized) |
| Minimum Pixel Size | 0.5 × 0.5 mm |
| Reflector Options | BaSO₄, ESR (3M), E60, Teflon (PTFE) |
| Surface Finish | All-side polished, white-painted, or as-cut |
| Coupling Window | One or two optical-quality polished faces |
LYSO Crystal vs. BGO vs. NaI(Tl) — Key Comparisons
- The table below highlights why LYSO crystal has become the material of choice for time-critical applications, displacing both BGO and NaI(Tl) in modern PET and high-energy physics detectors.
| Property | LYSO(Ce) ★ | BGO | NaI(Tl) |
|---|---|---|---|
| Density (g/cm³) | 7.1 ≈ BGO | 7.13 | 3.67 |
| Decay Time (ns) | 36 Fastest | 300 | 250 |
| Light Yield (ph/MeV) | ~33,000 | ~8,500 | ~38,000 |
| Energy Resolution @ 662 keV | ~8% Better | ~12% | ~6–7% |
| Emission Peak (nm) | 420 | 480 | 415 |
| Hygroscopic | No Easier | No | Yes |
| TOF-PET Suitability | Excellent Standard | Limited | Limited |
| Intrinsic Background | Low (Lu-176) | None | None |
Frequently Asked Questions
Q: Why is LYSO crystal the standard scintillator for TOF-PET?
- A:LYSO crystal combines a fast 36 ns decay time with high density (7.1 g/cm³) and a light yield sufficient for good energy resolution. These three properties together enable the sub-200 ps coincidence timing resolution required for Time-of-Flight PET — a combination that neither BGO (too slow) nor NaI(Tl) (too low density) can match simultaneously.
Q:How does LYSO crystal compare with BGO for PET applications?
A:While BGO and LYSO crystal share a similar density (~7.1 vs. 7.13 g/cm³), LYSO(Ce) offers 8× faster decay time (36 ns vs. 300 ns), approximately 4× higher light yield, and better energy resolution. For modern TOF-PET scanners, LYSO crystal is the clear choice. BGO remains relevant where intrinsic background from Lu-176 is a concern or where cost is the primary driver.
- Q: Is LYSO crystal non-hygroscopic? Does it need hermetic sealing?
A:Yes, LYSO(Ce) is completely non-hygroscopic. Unlike NaI(Tl) or LaBr₃(Ce), it can be handled and operated in ambient air without degradation. This greatly simplifies detector assembly and reduces system cost. No hermetic encapsulation is required for standard operating environments.
- Q: What customization options are available for LYSO(Ce) from Atr Crystal?
A: Atr Crystal accepts fully custom orders for LYSO crystal in any geometry: individual pixels and bars, polished slabs, linear (1D) arrays, and 2D pixelated arrays. We accommodate specific pixel dimensions (minimum 0.5 × 0.5 mm), reflector materials (BaSO₄, ESR, PTFE), and surface finishes. Sample quantities and volume production are both available. Contact our team with your drawing or datasheet for a tailored quote.
- Q: What is the intrinsic background of LYSO crystal and does it affect measurements?
A: LYSO crystal contains naturally occurring Lu-176 (2.6% isotopic abundance), which undergoes beta decay and produces background counts at ~88 keV and ~307 keV gamma lines. In most PET and imaging applications this background is negligible because the energy window of interest (511 keV for PET) is well separated. For low-background spectroscopy applications requiring zero intrinsic activity, GAGG(Ce) is the recommended alternative.
