--- title: Srl2(Eu) - Strontium Iodide High Resolution / Low Background Scintillators date: 2024-12-23T08:50:35Z modified: 2026-02-26T04:26:36Z permalink: "https://www.berkeleynucleonics.com/srl2eu-strontium-iodide/" type: page status: publish excerpt: "" wpid: 18992 --- [ ![](https://www.berkeleynucleonics.com/wp-content/uploads/CONFIGURE-YOUR-SCINTILLATION-DETECTORS.png) ](/customize-your-scintillation-detector) [](https://www.berkeleynucleonics.com/wp-content/uploads/sri2eu_strontium_iodide_bnc2.png) ![Strontium Iodide Srl2(Eu) Scintillators](https://www.berkeleynucleonics.com/wp-content/uploads/sri2eu_strontium_iodide_bnc2.png) [](https://www.berkeleynucleonics.com/wp-content/uploads/scionix_srl2eu2.png) ![Strontium Iodide Srl2(Eu) Scintillators](https://www.berkeleynucleonics.com/wp-content/uploads/scionix_srl2eu2.png) - [ Quote ](/customize-your-scintillation-detector) - [ Contact ](/contact-us/) - [ Datasheet ](#technical-resources-section) #### Srl2(Eu) – Strontium Iodide High Resolution / Low Background Scintillators Europium-doped strontium iodide (SrI₂:Eu) scintillation detectors are characterized by very high light yield and strong energy resolution across a wide gamma-ray energy range. The material is hygroscopic, has a relatively slow decay time, and contains no intrinsic radioactivity, which helps minimize background counts in low-level measurements. ##### Key Properties of SrI₂(Eu) Scintillation Detectors - **High Light Yield** – Produces bright scintillation pulses for improved energy resolution and detection efficiency. - **Good Energy Resolution** – Performs well from low energies (tens of keV) up to several MeV, suitable for precise gamma spectroscopy. - **No Intrinsic Radioactivity** – Low background contribution, beneficial for environmental monitoring, homeland security, and low-activity sample analysis. - **Hygroscopic Nature** – Requires protective encapsulation to prevent moisture damage. ##### Available Configurations - Encapsulated crystals with an entrance window for direct radiation entry. - Crystals integrally coupled to light sensors such as photomultiplier tubes (PMT) or silicon photomultipliers (SiPM). - Complete detector assemblies including the crystal, light sensor, and front-end electronics (preamplifier, shaping amplifier, etc.). These **SrI₂(Eu) scintillation detectors** are commonly used in gamma-ray spectroscopy, nuclear safeguards, environmental radiation monitoring, medical isotope identification, and research applications where high resolution and low background are important. ##### [Features](#features-section) ##### [Accessories](#accessories-section) ##### [Specifications](#specifications-section) ##### [Tech Resources](#technical-resources-section) ##### [Media](#media-section) ##### [Downloable Resources](#downloadable-section) ##### [Price List](#pricelist-section) ##### [FAQ](#faq-section) #### Overview SrI2(Eu) crystals are extremely bright and feature excellent proportionality. The material performs very well at both high and low energies. Typical energy resolutions are 3.5% FWHM for 662 keV and 6% FWHM for 122 keV. Srl2(Eu) is also quite radiopure. Due to its intrinsic self-absorption, the crystal requires special surface preparations techniques. Its long decay time requires long digital shaping time constants (>10 us) which can complicate high count rate behavior. The self-absorption limits the maximum size of the crystal to approximately 4 cm. #### Specifications **Density \[g/cm3\]** 4.6 **Hygroscopic** Yes **Wavelength of emission \[nm\]** 400-480 **Refractive index @ emission max** 1.85 **Decay time \[μs\]** 1-5 (size dependent) **Energy resolution \[%\] @ 662 keV** Approx. 3.5 % **Light yield \[photons/keV γ\]** 80 **Photoelectron yield \[% of NaI(Tl)\] (for γ-rays)** 120-140 **Ce concentration** 2 mol % ##### Typical Energy Resolution for 38 x 38 mm crystals **Energy** **Resolution** 59.5 keV 10% 122 keV 6% 356 keV 5% 662 keV 3.50% 1332 keV 3% 2600 keV 2.50% ##### Thorium Spectrum of 38 x 38 mm SrI2(Eu) Detector ![](https://www.berkeleynucleonics.com/wp-content/uploads/thorium_spectrum_of_38_x_38_mm_sri2eu_detector.jpg) ##### CS-137 Spectrum of 38 x 38 mm SrI2(Eu) Detector ![](https://www.berkeleynucleonics.com/wp-content/uploads/cs-137_spectrum_of_38_x_38_mm_srl2eu.jpg) #### Accessories ##### Free Online Training Module – An Introduction to Scintillation Crystals and Detectors Visit our [Training](http://t.sidekickopen69.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJN7t5XZsRzsQHMQK8vPf01G0W2zWM_W56dKFFf58RQqj02?t=https%3A%2F%2Fberkeleynucleonics.com%2Fonline-training-scintillation-crystals-and-detectors&si=5890484300939264&pi=098bd47e-b713-4682-d25a-962326ac848c) page to access the module or for more information ![](https://www.berkeleynucleonics.com/wp-content/uploads/training_photos-1-1024x684.jpg) #### Technical Resources [ Effects of Polarity on High Voltage Bias of Photomultipliers - Tech Note](https://www.berkeleynucleonics.com/download/23532/?tmstv=1778700934) [ Press Room - Scintillation Detectors: Attenuation Length Of Optical Emission](https://www.berkeleynucleonics.com/download/23538/?tmstv=1778700934) [ Press Room - Custom-Built Scintillation Detectors For Every Application](https://www.berkeleynucleonics.com/download/23544/?tmstv=1778700934) [ Press Room - Scintillator | What Are Scintillator Materials?](https://www.berkeleynucleonics.com/download/23550/?tmstv=1778700934) [ Press Room - From Crystal Growth To Assembly: The Manufacturing Process Of Custom Nal Scintillation Crystals](https://www.berkeleynucleonics.com/download/23556/?tmstv=1778700934) [ Press Room - Scintillation Crystals For PET: What You Need To Know](https://www.berkeleynucleonics.com/download/24167/?tmstv=1778700934) [ SrI2(Eu) Datasheet](https://www.berkeleynucleonics.com/download/24332/?tmstv=1778700934) #### Frequently Asked Questions (FAQ) #### Downloadable Resources Downloadable resources such as datasheets, firmware, software, drivers and products manuals. Alternatively, you can browse resources directly by visiting our [downloads page](/downloads). - [Product Datasheets](/downloads#scint-datasheets) - [Product Firmware](/downloads#scint-firmware) - [Product Software and Drivers](/downloads#scint-softwaredrivers) - [Product Manuals](/downloads#scint-manuals) #### Media ## Playlist ![BNC Model 525 Multi-Channel Digital Delay and Pulse Generator](https://img.youtube.com/vi/F0BZJNqskFE/maxresdefault.jpg) #### BNC Model 525 Multi-Channel Digital Delay and Pulse Generator 1:48 ![Introduction to the Model 525 GUI](https://img.youtube.com/vi/ypA-9_Nihcw/maxresdefault.jpg) #### Introduction to the Model 525 GUI 4:15 ![BNC Divide by Function for the Model 577 and Model 525](https://img.youtube.com/vi/7LDbxOY_pd0/maxresdefault.jpg) #### BNC Divide by Function for the Model 577 and Model 525 3:43 #### Price Lists [ Berkeley Nucleonics Price List 2026](https://www.berkeleynucleonics.com/download/19881/?tmstv=1778700934) [ ![](data:image/svg+xml;charset=utf-8,%3Csvg xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg' viewBox%3D'0 0 1500 138'%2F%3E) ](/customize-your-scintillation-detector)