CLYC Dual-Scintillation Crystal Detector for Neutron & Gamma Spectroscopy

Overview

The CLYC (Cs₂LiYCl₆:Ce) Dual-Scintillation Crystal Detector is a high-performance radiation detection component engineered for simultaneous, pulse-shape-discriminated neutron and gamma-ray spectroscopy in environmental monitoring, nuclear safeguards, and emergency response applications. Unlike conventional scintillators, CLYC leverages intrinsic dual-response capability: thermal neutrons interact primarily with enriched ⁶Li (via ⁶Li(n,α)³H reaction), while gamma rays deposit energy through Compton scattering and photoelectric absorption in the dense halide lattice. The resulting scintillation pulses exhibit distinct decay time constants—neutron-induced events decay with ~1 µs components, gamma-induced events with ~0.5–1.5 µs—enabling robust digital pulse shape discrimination (PSD) without external moderators or composite detector assemblies. This monolithic design eliminates inter-crystal interface losses and ensures consistent light yield across large-volume configurations (25 mm to 75 mm diameter/length), supporting high-efficiency counting in low-activity liquid or solid samples within regulatory-compliant environmental radiological assays.

Key Features

• Monolithic dual-mode scintillator: Simultaneous thermal neutron and gamma-ray detection in a single crystal matrix
• ⁶Li-enriched and ⁷Li-enriched variants available for optimized neutron capture cross-section or reduced intrinsic background
• Cylindrical geometry with standardized dimensions: 25×25 mm, 38×38 mm, 50×50 mm, and 75×75 mm active volumes
• Energy resolution ≤4.8% FWHM at 662 keV (¹³⁷Cs reference line), verified per IEC 61452 and ASTM E1452 protocols
• Hermetically sealed package options (S-series) for long-term stability in humid or chemically aggressive field environments
• PMT-integrated assembly (P-series): Pre-aligned, optically coupled crystal permanently mounted to bialkali photomultiplier tube; includes voltage divider and HV connector
• Thermal stability: Gain drift <±5% over 24-hour operation at ambient 23°C ±2°C, compliant with ISO/IEC 17025 calibration interval requirements

Sample Compatibility & Compliance

The CLYC detector is compatible with standard liquid scintillation counting (LSC) vials (20 mL glass or polyethylene), filter media (cellulose acetate, quartz fiber), soil slurries, and water concentrates prepared via co-precipitation or evaporation. Its high stopping power (density ≈3.3 g/cm³) and effective Z (~45) ensure efficient detection of low-energy gamma emitters (e.g., ²⁴¹Am, ⁶⁰Co, ¹³⁷Cs) and thermalized neutrons from ²⁵²Cf or moderated fission sources. All CLYC units are manufactured under AS9100D-controlled processes and conform to RoHS Directive 2011/65/EU. Device-level compliance supports integration into systems certified to IEC 62327 (handheld spectrometers), ANSI N42.34 (radiation portal monitors), and EPA Method 901.1 for gross alpha/beta and radionuclide-specific water analysis.

Software & Data Management

CLYC detectors interface seamlessly with industry-standard MCA firmware (e.g., ORTEC Maestro, Canberra Genie 2000, or custom LabVIEW-based DAQ) supporting real-time PSD gating, multi-channel spectrum accumulation, and nuclide identification libraries (including ¹⁵²Eu, ⁶⁰Co, ¹³³Ba, and neutron-capture signatures). Raw pulse data export (ASCII or binary .CNF) enables post-acquisition reprocessing for spectral deconvolution or Monte Carlo modeling (MCNP6/GADRAS). Audit trails, user access control, and electronic signature functionality align with FDA 21 CFR Part 11 requirements when deployed in GLP/GMP-regulated laboratories conducting environmental radioactivity reporting per 40 CFR Part 141 or ISO 11929:2019 uncertainty evaluation.

Applications

• Regulatory monitoring of tritium, ¹⁴C, and actinides in drinking water and wastewater effluents
• In-field neutron/gamma discrimination for nuclear material accountancy and spent fuel verification
• Low-background assay of environmental samples (air filters, sediment cores, biota) requiring sub-Bq/L sensitivity
• Calibration transfer standards for laboratory LSC systems operating under ISO/IEC 17025 accreditation
• Neutron dosimetry in mixed-field radiation environments (e.g., research reactors, accelerator facilities)
• Development of compact radiation portal monitors for border security and non-proliferation programs

FAQ

What neutron energy range does CLYC detect?
CLYC is optimized for thermal neutrons (E < 0.5 eV); fast neutron response requires external moderation (e.g., polyethylene reflector) and is not intrinsic to the crystal.
Is CLYC hygroscopic?
Yes—CLYC is moderately hygroscopic; all sealed (S-series) and PMT-integrated (P-series) units feature hermetic aluminum or stainless-steel housings with epoxy-sealed optical windows to prevent moisture ingress.
Can CLYC be used for alpha spectroscopy?
No—CLYC exhibits poor alpha/gamma pulse shape discrimination and low light yield for heavy charged particles; it is not suitable for alpha-emitting nuclides such as ²³⁸Pu or ²⁴¹Am quantification.
What is the typical light output relative to NaI(Tl)?
CLYC delivers ~20,000 photons/MeV for gamma rays and ~60,000 photons/neutron capture event, corresponding to ~75% of NaI(Tl)’s gamma light yield but significantly higher neutron-specific signal amplitude.
Does the detector require cryogenic cooling?
No—CLYC operates stably at ambient temperatures (−10°C to +40°C); thermoelectric cooling is optional only for ultra-low-noise spectroscopy below 100 keV.