Pulse and Delay Generators
Yes. The Model 577 is customizable using the ‘Ordering Chart’. Select how many channels you would like for options such as high power outputs, optical isolation, impedance matching, etc. Channels are paired.
A digital delay generator (DDG) produces precise, programmable time delays between trigger inputs and output pulses — often with picosecond-level resolution. While a standard pulse generator creates pulses with defined width and repetition rate, a DDG adds precise, independent delay control on each output channel. This is essential for synchronizing multiple instruments in laser experiments, LIDAR systems, particle accelerators, and pump-probe spectroscopy setups where timing relationships between events must be exact.
Channel count depends on how many independent timing signals your experiment or system requires. Single-channel units work for simple trigger-delay applications, while multi-channel models (BNC offers up to 24 channels in the 588B) are used to synchronize cameras, lasers, shutters, detectors, and other instruments simultaneously. In multi-channel systems, outputs can typically be set with independent delays, widths, and amplitude levels per channel. Opt for a rackmount unit if channel density and stackability are priorities.
You can, but there are some considerations to make. A current driver may be less problematic. See https://www.berkeleynucleonics.com/february-15th-2022-pitfalls-using-pulse-generator-drive-laser-diode for further reading.
In pump-probe spectroscopy and ultrafast laser experiments, BNC digital delay generators (Models 555, 575, 577) serve as the master timing hub. The DDG receives a single trigger — typically from a laser oscillator or sync output — and generates multiple independently delayed output pulses, each with picosecond-level timing resolution. These outputs trigger the pump laser, probe laser, shutter, detector gate, or camera in a defined sequence. The ability to set independent delays, widths, and polarity on each channel within a single instrument eliminates the need for multiple cascaded delay boxes, reducing jitter accumulation and simplifying the timing chain.
BNC digital delay generators deliver timing resolution as fine as 250 ps (Models 575, 577) with RMS jitter typically under 50 ps for standard configurations. For the most demanding accelerator and particle physics applications — where sub-100 ps jitter budgets are required across multiple channels — the Model 765 provides 70 ps rise time with 800 MHz bandwidth. Timing accuracy is also affected by the trigger source quality; BNC recommends using a stable, low-jitter external reference for the best system-level performance. Contact BNC’s applications team for a jitter budget analysis specific to your experiment.
The Model 745T-20C offers 20 channels per enclosure and can be daisy chained with additional units to a single trigger. However, for complex multi-channel applications, contact the factory. We can offer a custom card-level solution which may be more cost effective.
Channel indicator illumination indicates the channel is enabled a/o pulsing. Front panel indicators are convenient if your control GUI is in a different location or you are running multiple software applications.
Yes, Model 525 can be powered by standard USB phone chargers and can run without the aid of a PC. A PC is only needed to set or change the pulse characteristics.
Yes. The Rise and Fall time for the Model 765 is 70ps. The amplitude is +/- 5V and there are 2 and 4 channel versions available.
Yes. The Model 765 allows you to set the pulse top and pulse baseline from -2.5V to +2.5V.
Waveform Generators
A function generator produces standard periodic waveforms — sine, square, triangle, and ramp — at fixed shapes defined by the instrument. An arbitrary waveform generator (AWG) lets you define any custom waveform by uploading a point-by-point data file, making it possible to replicate real-world signals, simulate specific modulation schemes, or generate one-time transient pulses. AWGs are preferred whenever the signal shape is application-specific rather than standard.
Sample rate determines the highest frequency component your waveform can accurately reproduce (you need at least 2–5x the highest signal frequency as sample rate). Memory depth determines how long a waveform can be before it repeats. For high-frequency radar or communications waveforms, models like the BNC 686 (20 GS/s, 14-bit) provide high fidelity. For lower frequency biomedical or motor control waveforms, the 645 (50 MHz) or 670C (180 MHz) are more appropriate and cost-effective.
Yes, select BNC AWG models support differential output configurations, which are important for driving differential input devices, reducing common-mode noise, and interfacing with high-speed ADCs or modulators. Contact BNC’s applications team to confirm which output topologies are available for your target model and frequency range.
Digital data from the rear panel External Trig/Gate/FSK/BPSK connector is the modulation source.
Any user data would be downloaded from a host computer and stored in the arb memory. Any kind of zero-intersymbol-interference or spectral shaping filtering would be done mathematically on the PC before the download.
This rear panel connector can be used to insert modulation signals onto a carrier. In conjunction with modes such as AM, FM, SSB, Ext Mod can even provide communication signals at the SIG OUT connector.
Use the following settings for HyperTerminal – Baud rate: 9600, Data bits: 8, Parity: None, Stop bits: 1, Flow control: None, Emulation: VT 100
155 uV adjustments can be made on the key pad or spinner knob. Each “click” of the spinner makes this minimum adjustment. (Turning the spinner fast will allow it to slew millivolts or volts.)
No, the clamp simply preserves the amplitude of the pulse when the tail time is long compared to the desired rep rate. This feature is accomplished by clamping the pulse to the baseline before the exponential decay is completed thus allowing the next pulse to start from the baseline rather than some point on the tail. It is recommended that the delay time be set to 3 or 4 us to allow a full recovery to the base line.
Symmetry would require a fast discharge of capacitors used to produce exponential tails. The critical issue in the PB-5 is to preserve exponential decay with a clean return to the baseline. The PB-5 meets the same fall time specification as the PB-4 with a cleaner signal as it decays to the baseline – allowing twice the rep rate (500 kHz) as the PB-4.
Best results are accomplished by multiple sweeps at the shortest ramp time (90 seconds). Set the number of sweeps to 999, giving a run time of just over 24 hours. For unusually demanding needs, the measurement can be repeated for several days. Since any temperature corrections are made between sweeps (not during the ramp), ramp times of 15 minutes may not give the required accuracy. Short ramps allow good random statistics for all channels as long as many sweeps are made.
Yes, a RS-232 port is available for this feature. Put the PB-5 in “remote” using the main menu. If the manual or PC commands are not available, type “help” and all commands will be listed.
RF & Microwave
A microwave signal generator produces a precise RF or microwave frequency output — typically ranging from a few kHz to tens of GHz — that serves as a reference or stimulus signal in test setups. Engineers use them to characterize amplifiers, test receivers, simulate radar signals, verify satellite link budgets, and calibrate spectrum analyzers. BNC’s signal generators cover 100 kHz to 54 GHz and are widely used in defense, aerospace, quantum computing, and telecommunications R&D.
The most important specifications are frequency range, phase noise, output power range, and switching speed. Phase noise is especially critical for radar, communications, and quantum computing applications — lower phase noise (measured in dBc/Hz at a given offset) means a cleaner signal. For multi-channel setups, channel-to-channel isolation and phase coherence also matter. BNC offers dedicated low-noise (LN) and ultra-low-noise (LN+) options for demanding applications
Phase noise is the noise produced by fast, short term fluctuations in a signal. Phase noise diminishes the signal quality and increases error rates in communication links. Although there is no such thing as “no” phase noise, the less you have, the better.
Phase noise is the random, short term fluctuations in the phase of a waveform caused by time domain instabilities (jitter). Phase noise looks at the jitter within a single repetition.
Yes. All BNC signal generators support GPIB, USB, LAN (Ethernet), and in many cases RS-232 interfaces, and are compatible with SCPI command sets used in LabVIEW, Python, and MATLAB environments. Most models include a software GUI for PC control. For high-channel-count applications, multi-unit synchronization is available via external reference inputs (typically 10 MHz).
The key difference between LN and LN+ is that LN+ will have better long-term performance—for example, a better Allan variance for a longer time. For short-time performance, they are identical.
Here’s another example…Option LN adds a 100 MHz OCXO on the ref board, applying to all channels. Option LN+ will do the same. The only difference is that the OCXO will have better long-term stability.
You can incorporate either LN or LN+. Options can’t be combined and priced per unit.
The Model 865 is a new product for 2018. The 1 GHz phase noise is extremely low in the standard unit (-87 dBc/Hz @ 10 Hz offset ). For even more demanding applications, we can install a special Low Noise option as in previous models. We believe the performance of the 865 with LN option is the market leading signal source in this class. (-100dBc/Hz @ 10 Hz offset)
To check price and delivery, to place a Purchase Order, or to expedite an existing order, please call 415-453-9955, email info@berkeleynucleonics.com or fill out a Get a Quote form. Typical response time is less than 2 hours.
Yes. The Model 577 is customizable using the ‘Ordering Chart’. Select how many channels you would like for options such as high power outputs, optical isolation, impedance matching, etc. Channels are paired.
The Multi-Channel Model 855 allows for up to 4 channels in each 1U 19″ rack Mount enclosure. This design can be stacked as needed. We believe this is the most compact multi-channel offering with high performance on the market.
The Model 845 is a small footprint benchtop Microwave Signal Generator with very high performance. The space saving packaging eliminates most of the front panel controls in favor of a software GUI that can be developed and enhanced over time. The low power requirements are equally resourceful, even allowing for a battery option.
The Model 855B is BNC’s flagship multi-channel RF/microwave signal generator, offering up to 4 phase-coherent channels in a 1U rack enclosure from 300 kHz to 42 GHz. Its standout features include industry-leading phase noise, independent per-channel control, and a compact form factor. [Full product overview →] – https://www.berkeleynucleonics.com/july-5th-2022-model-855b-product-high…
Moore’s Law and quantum computing follow fundamentally different scaling paths
Moore’s Law tracks transistor density, while quantum computing scales by qubit count and error rate. [Learn more on our Quantum Computing Course →]
To design a receiver, engineers will need to select transistors for the design. You could obtain a sample of the transistor and perform noise parameter measurements while possibly setting the transistor to different power consumption settings and also varying the temperature. This gives the engineer complete information on how to select “matching” components (inductors and capacitors) that go at the input of the transistor to obtain the lowest noise figure and ultimately allows him to design the best performing receiver.
Pulsed Power
Pulsed power delivers high-energy electrical pulses over very short durations — typically nanoseconds to microseconds — producing instantaneous peak power levels far exceeding what continuous systems could safely sustain. This concentrated energy is used in applications like laser diode driving, plasma generation, EMC testing, pulsed electron beam systems, and high-energy physics experiments. Continuous power systems deliver steady-state current and voltage, whereas pulsed power systems store energy and release it in controlled, precisely timed bursts.
BNC’s pulsed power product line (DEI division) is designed to drive resistive, inductive, and capacitive loads across a wide range of impedances. Common loads include laser diodes, Pockels cells, plasma chambers, solenoids, and spark gap electrodes. Models are available with bipolar output and high-current output for demanding laser diode driver applications. Specify your load impedance and required pulse parameters when requesting a quote.
Yes — while BNC’s pulse delay generators (such as the Model 577) are primarily designed as precision timing instruments, they are frequently used to trigger or gate high-voltage pulsed power systems. In these setups, the DDG provides the precise timing signal that initiates the pulsed power event, with the actual high-voltage switching handled by a separate driver stage. For applications requiring direct high-voltage pulsed output, BNC’s DEI division Pulsed Power product line (PVX and PCX series) is designed specifically for those loads.
Yes — BNC’s DEI pulsed power systems and digital delay generators are frequently integrated in the same test setups. The DDG (e.g. Model 577 or 588) provides precise timing control — triggering the pulsed power event at a defined delay and pulse width — while the DEI high-voltage unit (such as the EVO series power supply or PVX/PCX pulsers) delivers the actual high-current or high-voltage output. This combination is used in plasma research, semiconductor testing, laser diode characterization, and synchronization of multiple instruments. BNC’s applications team can assist with integration guidance.
High-voltage pulsed power systems require careful attention to electrical isolation, grounding, and discharge procedures. Key precautions include using properly rated cabling and connectors, ensuring all personnel are trained on lockout/tagout procedures, maintaining safe clearance distances, and never working alone near energized high-voltage circuits. BNC’s DEI division pulsed power equipment includes built-in safety interlocks and is designed to comply with relevant electrical safety standards. Always consult the product manual and your facility’s safety officer before installation.
Radiation Detection & Isotope Identification
See this article for details – https://www.berkeleynucleonics.com/july-27th-2022-cerium-bromide-and-sodium-iodide-detectors
Neutrons do not produce ionization directly in scintillation crystals but can be detected through their interaction with the nuclei of a suitable element. In a 6LiI(Eu) scintillation crystal, for example, neutrons interact with 6Li nuclei to produce an alpha particle and a triton (tritium nucleus), which both produce scintillation light that can be detected. Another Li-containing scintillator is CLYC.
Also enriched 6Li containing glass can be used, doped with Ce as an activator. Alternatively, Boron or Gadolinium containing inorganic scintillators can be used but these scintillators are not common. One alternative technique is to construct a large area thermal neutron detector using 6LiF/ZnS(Ag)screens. These can then be read out via green wavelength shifters by PMTs or SiPMs.
Alpha radiation, beta radiation, gamma radiation, and x radiation. Neutron radiation is also encountered in nuclear power plants and high-altitude flight and emitted from some industrial radioactive sources.
Gamma ray spectroscopy has evolved from large lab-bound NaI(Tl) systems requiring external MCAs, to compact handheld RIIDs with on-board isotope libraries and smartphone interfaces. Modern detectors like the SAM 940+ offer sub-2% energy resolution with real-time field identification. [Read the full history →] – https://www.berkeleynucleonics.com/december-23rd-2020-how-gamma-ray-spectroscopy-has-evolved
Our SAM III series of equipment (SAM 950, SAMpack and SAMmobile 150) is compatible with FEMA’s RadResponder network at no additional cost to the end user.
The smart phone technology lends itself to spectroscopy with a simplified and intuitive operation. The advantages are many fold:
- Smart phone operation is wide spread allowing the user to quickly adapt to touch screen use and utilizing many cell phone features.
- The device (PDA) is a quality product which gives the SAM III products reliable operation with many first-ever capabilities. The display has excellent linearity and resolution with color coded spectra and one-finger operation of the cursor. Many features are automated, for example, auto calibration and stabilization which are clearly displayed.
- Detaching the PDA (SAM 945, RD120) allows convenient control of the instrument from a distance (bluetooth control). With the RD120 SAMpack monitoring can be clandestine with or without earphones.
- When monitoring waste or highly active material the user can be at a safe distance (20 feet or more) and have complete control of the spectrometer which includes making measurements, taking multiple acquisitions, manipulating the spectrum, etc. Therefore, the ALARA safety practices are easily accomplished.
- General cell phone features are incorporated into the operation of the SAM. For example, taking a picture and adding text or video describing details of the source being measured. This added information is included with the report and spectrum.
When using the Variable Alarm Mode (as opposed to Fixed Alarm Mode) a low threshold can be set to start the acquisition during a search for radionuclides. A low threshold which triggers the start of an acquisition is important for achieving high sensitivity. However, changes in the background during surveillance can cause false triggers that may result in false identification of isotopes. To prevent false triggers from happening BNC uses a scheme called “Auto Variable Trigger”. This is a threshold adjustment that continuously optimizes the threshold setting automatically. Those performing environmental surveillance will find this mode especially valuable as it allows identification of NORM isotopes with the highest sensitivity possible during changes in NORM.
The sigma trigger allows a low threshold for sensing a radioactive source while being unaffected by false triggering due to changes in background (sigma indicates standard deviations over background). This provision automatically updates the current background which yields higher sensitivity while eliminating false triggers due to changing ambient background. This feature allows the user to survey a large area without needing to continuously stop and store a new and different background. A sigma setting of 4 is recommended.
The example given here is for a typical background of 7 urem/hr (70 nSv/hr) which corresponds to about 250 gamma counts per second (cps). When a Ra-226 source is detected there will be an alarm at background levels but a firm ID will not occur until the cps reaches about twice the background level (500 – 600 cps for this example). This higher cps level for ID is expected since Ra-226 has many peaks and many are very low in abundance (sometimes referred to as Branching Ratio, Branching intensity or intensity of peaks.)
In addition Ba-133 has similar peaks with much higher branching intensities (about 20 times higher) which add to the complexity of identifying Ra-226 especially at low cps. The library is carefully designed to take this into account but moving closer to the source or waiting a little longer for a solid ID is always important (Ba-133 ID may be seen momentarily but will cease as statistics improve). Identifying two or more isotopes each with low abundant lines (peaks) may also require moving closer to the source and possibly waiting longer to obtain good performance.
U-238 is another example of a source with low abundant lines and may take up to 30 seconds or more to identify at minimum count rate (<500 cps). Users must realize that the basic specifications which are given for the Cs-137 standard is the result of a very high branching intensity (>85%) – whereas the branching intensity of U-238 lines are less than 1% of Cs-137. It is therefore expected that acquisitions on some sources will take a little longer but it is common practice to use acquisitions of at least 1 minute and to move closer to the source if possible.
The SAM III instruments have a maximum count rate of 100,000 CPS and 150,000 CPS depending on the amount of background and the number of energy peaks being processed.
Berkeley Nucleonics provides the standard ANSI N42 compliant libraries for SNM, Medical, Industrial and NORM. Also a user defined library is provided. Finally, an expanded ANSI compliant library is available for CeBr and LaBr detector upgrades. New medical libraries and isotopes are updated through the product’s free apps, PeakGo and PeakAbout.
Yes. The SAM 940+ is capable of detecting and identifying special nuclear material (SNM), including HEU and plutonium, using its high-resolution NaI(Tl) or optional CsI detector and on-board isotope library. It meets ANSI N42.34 Type C performance requirements. [Detailed application note →] https://www.berkeleynucleonics.com/march-24th-2022-identifying-nuclear-and-special-nuclear-material-sam-940
For routine neutron confirmation, or applications where an integrated, clandestine device is required, BNC offers an Li6 solid state neutron detector internal to the gamma detector module. The benefits include a lower cost, light weight, smaller volume. This detector is available in the SAM 940-2GN and 940-3GN.
The Li6 scintillator crystal (neutron detector) is embedded in the NaI scintillator crystal (gamma detector). Both scintillator crystals share the same power and amplification circuits. The MCA processes data from both materials and discriminates Neutron counts from Gamma counts. Secondary confirmation of Neutron counts can be accounted for quickly through the introduction of a tin or lead shield, or a slight retreat in the operator’s position. Contact the factory for additional training.
The Model SAM 950 has a highly upgraded power source with rechargeable lithium-ion batteries. These batteries give reliable operation for over 8 hours before requiring recharge.
BNC generally recommends a 2x4x16 inch detector unless greater efficiency is needed at high photon energies. For energies that include photons from U-235 and Pu-239 there is negligible difference between the two sizes. This means that the photons from both U-235 and Pu-239 are fully absorbed in either size detector. For isotopes like Cs-137 and U-238 some differences begin to show. The photon energy at 2615 keV (which is an indication of highly enriched material) is still easily detected in the 2x4x16 inch detector because the background is quite low in this region. Contact the factory for application specific support. The data for several common isotopes is shown below:
2x4x16
- 100% absorption (abs) at 186 keV (includes all energies of U-235)
- 87% abs at 414 keV (includes Pu-239 at 332, 375 and 414 keV)
- 75% abs at 662 keV (Cs-137)
- 67% abs at 1000 keV (U-238)
- 52% abs at 2615 keV
4x4x16
- 100% abs at 186 keV (includes all energies of U-235)
- 98% abs at 414 keV (includes all energies of Pu-239)
- 95% abs at 662 keV (Cs-137)
- 89% abs at 1000 keV (U-238)
- 76% abs at 2615 keV
The MetRad1 has 2 different LED indicators and 2 different alarm tones to notify the operator which type of alarm is present.
The nukeALERT contains an Adjustment Switch that allows you to manually adjust the lowest level sensitivity of the detector. This should not be casually adjusted since it reduces the highest sensitivity of the detector. Usually, this switch is adjusted at the factory or by our tech support team. It is important to track your minimum settings so you don’t end up with 50 nukeALERT’s, each with different sensitivity settings.
No. The nukeALERT 951 recalibrates itself on power up and can be operated for many years simply by changing the battery.
The Model 907 measures alpha, beta, and gamma radiation. The device is a health and safety instrument that is optimized to detect low levels of radiation.
When the nukeALERT is turned on, it calibrates itself to the natural radiation background. When the nukeALERT notices the background has reduced, it will recalibrate itself to improve the sensitivity. When you are traveling, your device may detect a lower natural background environment and recalibrates itself to ensure maximum detector sensitivity. You often see a reduced background count and a recalibration if you take the nukeALERT into a car or truck, for example.
Scintillation Detectors
A scintillation detector converts ionizing radiation (gamma rays, neutrons, or charged particles) into visible light pulses, which are then detected and measured by a photomultiplier tube (PMT) or silicon photomultiplier (SiPM). The material used for scintillation — such as NaI(Tl), CeBr3, or CLYC — determines the detector’s energy resolution, timing performance, and sensitivity to specific radiation types. BNC manufactures custom scintillation detectors across a wide range of crystal materials for research, defense, nuclear medicine, and environmental monitoring applications.
A scintillator is a material that exhibits scintillation, which refers to the emission of light when the material interacts with ionizing radiation. Scintillators are widely used in various fields, including radiation detection, medical imaging, and high-energy physics. Different types of scintillators exist, and some common examples include NaI (sodium iodide), LaBr (lanthanum bromide), CeBr (cerium bromide), and CsI (cesium iodide). These scintillators have distinct properties and are utilized in specific applications. Each of these scintillators has its advantages and suitability for specific applications, depending on factors such as energy resolution, light output, decay time, and cost. Researchers and engineers select the most appropriate scintillator based on the requirements of their particular application.
To detect y-rays efficiently, a material with a high density and high effective Z (number of protons per atom) is required. Inorganic scintillation crystals meet the requirements of stopping power and optical transparency. Their densities ranging from roughly 3 to 9 g/cm3 makes them very suitable to absorb penetrating radiation (γ-rays). Materials with high Z-values are used for γ-ray spectroscopy at high energies (> 1 MeV).
Because photoelectron statistics (or electron-hole pair statistics) play a key role in the accurate determination of the energy of the radiation, the use of scintillation materials with a high light output is preferred for all spectroscopic applications. The scintillator emission wavelength should be matched to the sensitivity of the light detection device that is used (PM, SiPm or photodiode).
Scintillation light pulses (flashes) are usually characterized by a fast increase of the intensity in time (pulse rise time) followed by an exponential decrease. The decay time of a scintillator is defined by the time after which the intensity of the light pulse has returned to 1/e of its maximum value. Most scintillators are characterized by more than one decay time and usually, the effective average decay time is mentioned. The decay time is of importance for fast counting and/or timing applications.
To detect fast changes in transmitted intensity of X-Ray beams, such as in CT scanners or luggage X-ray detectors, crystals are required exhibiting low afterglow. Afterglow is defined as the fraction of scintillation light still present for a certain time after the X-Ray excitation stops. Afterglow originates within a millisecond and can last hours in long decay time components. Afterglow in most halide scintillation crystals can be as high as a 5-10 percent after 3 ms. The long duration afterglow in e.g. CsI(Tl) can be a problem for many applications. Afterglow in halides is believed to be intrinsic and correlated to certain lattice defects. BGO, CeBr3, and Cadmium Tungstate (CdWO4) crystals are examples of low afterglow scintillation materials.
Each scintillation material has a characteristic emission spectrum, with wavelength and intensity. The shape of this emission spectrum is sometimes dependent on the type of excitation (photons/particles).
Emission spectra of NaI(Tl), CsI(Tl) and CeBr3, scaled on maximum emission intensity.
Also a typical quantum efficiency curve of a bialkali photocathode and a Silicon Photomultiplier (SiPm) are shown above.
This emission spectrum is of importance when choosing the optimum readout device (PMT / photodiode/SiPm) and the required window material. The graph above shows the emission spectrum of some common scintillation materials.
The most widely used scintillation material for gamma-ray spectroscopy is Sodium Iodide, NaI(Tl). It is hygroscopic and is only used in hermetically sealed metal containers to preserve its properties. All water-soluble scintillation materials should be packaged in such a way that they are not attacked by moisture. Some scintillation crystals may easily crack or cleave under mechanical pressure whereas others are plastic and only will deform like CsI(Tl). See our Table of Properties or Table of Applications for material specific comments.
SiPMs are an alternative readout method to standard PMTs. With respect to signal processing and spectroscopic behavior, SiPMs behave differently compared to standard PMTs. The elements are typically 3×3 or 6×6 mm and can be combined into matrices. For applications where a small crystal size and low voltage operations are required SiPM readout can be a good choice. The energy resolution and noise level achievable with SiPM readouts depend on crystal dimensions, scintillation material, and how much area is covered by the SiPMs
For larger scintillation crystals, it is important to strategically place as few SiPMs as possible. It is impractical to use too many SiPMs because the capacitive notice on the signal
If you are interested in this readout method, please contact us
The light output (number of photons per MeV gamma) of most scintillators is a function of temperature. This is caused by the fact that in scintillation crystals, radiative transitions, responsible for the production of scintillation light, compete with nonradiative transitions (no light production). In most scintillation crystals, the light output is quenched (decreased) at higher temperatures. An example to the contrary is the fast component of BaF2 which the emission intensity is essentially temperature independent.
The scintillation process usually involves three stages, production, transport and quenching centers. Competition between these three stages and all three behaving differently with temperature creates a complex temperature dependence for scintillation light output.
Below is a chart with the temperature dependence of common scintillation crystals.
Temperature dependence of the scintillation yield of NaI(Tl), CsI(Tl), BGO and CeBr3
For most applications, the combination of the temperature dependent light output of the scintillator together with the temperature dependent amplification of the light detector should be considered.
The doped scintillators NaI(Tl), CsI(Tl) and CsI(Na) show a distinct maximum in intensity whereas many undoped scintillators such as BGO show an increase in intensity with decreasing temperature. The temperature dependence of the Ce doped scintillators LBC, CeBr3 and YAP:Ce is significantly less than that of other scintillators.
See this article for details – https://www.berkeleynucleonics.com/july-27th-2022-cerium-bromide-and-sodium-iodide-detectors
- Density and atomic number (Z)
- Light output (wavelength + intensity)
- Decay time (duration of the scintillation light pulse)
- Mechanical and optical properties
- Cost
Material selection depends on what type of radiation you’re measuring, required energy resolution, operating temperature range, count rate, and cost constraints. NaI(Tl) is the most widely used general-purpose gamma detector. CeBr3 offers superior energy resolution without requiring cooling. LaBr3 provides excellent timing and resolution but is more expensive. CLYC and CLLBC are dual-mode gamma/neutron detectors suitable for SNM detection. SrI2 delivers the highest resolution available in a room-temperature scintillator. BNC’s applications team can recommend the best material based on your specific requirements.
There is a great variety of choices to consider. Selecting the right material, geometry, readout and electronics are only a start. See https://www.berkeleynucleonics.com/february-11th-2022-customizing-your-scintillation-detector for further reading.
Yes – an important aspect of your product selection. See https://www.berkeleynucleonics.com/february-23rd-2022-ruggedized-detectors-customized-scintillators-field for further reading.
Neutrons do not produce ionization directly in scintillation crystals but can be detected through their interaction with the nuclei of a suitable element. In a 6LiI(Eu) scintillation crystal, for example, neutrons interact with 6Li nuclei to produce an alpha particle and a triton (tritium nucleus), which both produce scintillation light that can be detected. Another Li-containing scintillator is CLYC.
Also enriched 6Li containing glass can be used, doped with Ce as an activator. Alternatively, Boron or Gadolinium containing inorganic scintillators can be used but these scintillators are not common. One alternative technique is to construct a large area thermal neutron detector using 6LiF/ZnS(Ag)screens. These can then be read out via green wavelength shifters by PMTs or SiPMs.
Radiation damage is defined as the change in scintillation characteristics caused by prolonged exposure to intense radiation. This damage manifests itself by a decrease of the optical transmission of a crystal which causes a decrease in pulse height and deterioration of the energy resolution of the detector. Radiation damage other than radio-activation is usually partially reversible; i.e. the absorption bands often disappear slowly in time; some damage can be annealed thermally.
In general, doped alkali halide scintillators such as NaI(Tl) and CsI(Tl) are rather susceptible to radiation damage. All known scintillation materials show more or less damage when exposing them to large radiation doses. The effects usually can only be observed clearly with thick (> 5 cm) crystals. A material is usually called radiation hard if no measurable effects occur at a dose of 10.000 Gray. Examples of radiation hard materials are CeBr3 and YAP:Ce.
BNC Scientific
Yes. bGamma is a full spectroscopic package for NaI, HPGe and other spectroscopy applications. It is the only spectroscopy package that is Mac and Windows compliant.
Ordering Information / Contact Us
To check price and delivery, to place a Purchase Order, or to expedite an existing order, please call 415-453-9955, email info@berkeleynucleonics.com or fill out a Get a Quote form. Typical response time is less than 2 hours.
ur main headquarters is in California. Our address is 2955 Kerner Blvd, San Rafael CA 94901. We have sales offices throught the United States and in many European and Asian countries. We also have a nationwide network of approved trainers to handle product training and installation. Contact the factory at 415-453-9955 or info@berkeleynucleonics.com for your closest resource.
