Fast Timing Discriminators: Leading Edge, Constant Fraction, Single and Multiple Input

​Fast timing discriminators enable the counting of narrow pulses at very high counting rates, and/or precisely marking the arrival time of these same pulses. They are designed to achieve the best time resolution and the highest counting rates by operating on the fast-rising detector signal.

A range of single-channel and multi-channel fast timing discriminators is available from ORTEC, employing both leading edge timing and the more advanced, ORTEC-invented constant-fraction timing.

​CF8000 Octal Constant Fraction Discriminator
583B Constant Fraction Differential Discriminator/SCA
584 Constant Fraction Discriminator
935 Quad 200-MHz Constant Fraction Discriminator
9302 Amplifier Discriminator
9307 pico Timing Discriminator
9327 1-GHz Amplifier and Timing Discriminator

Single Channel Analyzers: Timing, Non-timing, Integral, and Differential

A single-channel analyzer (SCA) produces an output logic pulse on the condition that the peak amplitude of its input signal falls within the pulse-height window that is established with two preset threshold levels. ORTEC provides two basic types or classifications of SCAs: non-timing SCAs and timing SCAs. Non-timing SCAs produce an output pulse if the input signal is within the window settings. Timing SCAs produce an output logic signal precisely related in time to the occurrence of the event being measured.

ORTEC offers a range of timing and non-timing SCAs. 

​550A Single Channel Analyzer
551 Timing Single Channel Analyzer
552 Pulse Shape Analyzer and Timing SCA
583B Constant Fraction Differential Discriminator/SCA
590A Amplifier and Timing Single Channel Analyzer
850 Quad Single Channel Analyzer
925-SCINT ACE-MATE Preamplifier, Amplifier, Bias Supply, and SCA

Multichannel Analyzers

​​Basic Analog MCAs for routine applications:
Standalone USB Connected MCAs
NIM Modular MCAs
Digital all-in-a-PMT-Base MCAs with Bias Supply and DSPs for use with Scintillation Detectors
Integrated Digital Workstation MCAs for use with HPGe Detector systems
Portable Digital MCAs for HPGe and Scintillation Detectors



​DSPEC-Jr. 2.0











Digital Current Integrator

​The ORTEC Model 439 Digital Current Integrator was designed to accurately measure dc currents or the average value of pulse currents such as produced by accelerator beams. It digitizes the input current by producing an output pulse for specific values of input charge. The Model 439, when combined with a preset counter, forms a digital charge integrator. When it is combined with a counter and timer, a digital electrometer is obtained. For this purpose the EASY-NIM 928-COUNT2 is highly recommended

HV Bias/NIM Power Supplies and Bins

​ORTEC offers two types of power supplies for use with NIM instrumentation: power supplies that provide operating voltages for a detector (more properly called detector bias supplies or “HV” supplies) and power supplies that provide the necessary operating voltages for NIM Modular electronic instruments in the form of a NIM “Bin” with associated power supply.

All ORTEC NIM instrumentation conforms to the May 1990 Revision of the NIM standard (formerly TID 20893 (Rev) and NIM/GPIB). Please refer to DOE/ER-0457T, U.S. NIM committee, May 1990; Standard NIM Instrumentation System, NTIS, U.S. Department of Commerce, Springfield, Virginia 22161

​428 Detector Bias Supply
495 Power Supply
556 and 556H High Voltage Power Supply
659 5-kV Detector Bias Supply
660 Dual 5-kV Detector Bias Supply
710 Quad 1-kV Bias Supply
4001A/4001C NIM Bins
4002A 96-W Power Supply for NIM Bins
4002D 160-W Power Supply for NIM Bins
4002E BlackMax Power Supply for NIM Bins
4002P Portable Power Supply
4003 Preamplifier Power Output
4006 MiniBin and Power Supply

Amplifiers for Energy Spectroscopy, and Timing: Single and Multiple Input

The amplifier is one of the most important components in a pulse processing system for applications in counting, timing, or pulse amplitude (energy) spectroscopy, providing the pulse-shaping controls needed to optimize the performance of the analog electronics.

Different models of amplifiers are available from the broad ORTEC NIM product range to suit different detector types and applications, from energy spectroscopy through counting, timing and fast counting. 

​FTA820A Octal Fast Timing Amplifier
427A Delay Amplifier
460 Delay Line Amplifier
474 Timing Filter Amplifier
533 Dual Sum and Invert Amplifier
570 Amplifier
572A Amplifier
575A Amplifier
579 Fast Filter Amplifier
590A Amplifier and Timing Single Channel Analyzer
671 Spectroscopy Amplifier
672 Spectroscopy Amplifier
673 Spectroscopy Amplifier and Gated Integrator
855 Dual Amplifier
863 Quad Timing Filter Amplifier
925-SCINT ACE-MATE Preamplifier, Amplifier, Bias Supply, and SCA
9302 Amplifier Discriminator Data Sheet
9309-4 Quad Fast Amplifier
9310-16 Sixteen Channel Fast Amplifier
9327 1-GHz Amplifier and Timing Discriminator

Time-to-Amplitude Converters and Calibrators

​A Time-to-Amplitude Converter (TAC) can achieve exceptional precision by using an analog technique to convert small time intervals to pulse amplitudes. When a timing application demands picosecond precision, a time-to-amplitude converter is a prime candidate. A time-to-amplitude converter is a productive solution for measurements less than 10 μs when time resolutions from 10 ps to 50 ns are required. 

The time calibrator provides accurate calibration of the time scale in these measurements.

​566 Time to Amplitude Converter
567 Time to Amplitude Converter/SCA

Pulse Generators

Pulse generators provide electronic pulses which mimic events from radiation detectors and are useful in set-up, diagnostics, and noise measurement in spectroscopy systems.

Two models are available:

The 480 is a basic, simple to operate pulser which derives its frequency from the POWER line. It features negative and positive polarity, <10 ns, rise time and a 200 or 400 µs decay time constant. The 480 is ideal for basic set up and troubleshooting. 

The 419 offers greater flexibility in terms of pulse height and rise-time settings, and offers line frequency or 70 Hz pulse rates.

​419 Precision Pulse Generator
480 Pulser

ORTEC electronics provide a critical role in a majority of gamma spectroscopy counting labs, physics research institutes and other gamma spectroscopy applications globally.

The ORTEC range of modular electronics includes instruments in NIM and CAMAC formats as well as other modular instruments, such as photomultiplier bases, preamplifiers and other accessories. ORTEC also offers modular instruments for pulse height spectroscopy, fast timing, counting, high voltage power supplies and other special functions.

In addition to modular electronics ORTEC is also an industry leader in digital electronics. Whether the fully integrated DSP based workstation family of DSPECs, or portable, field friendly DigiDARTs, ORTEC offers a full suite of digital solutions to meet all your needs.

Delays, Gates and Delay Generators, Logic Modules, and Linear Gates

Delays, Gate and Delay Generators, Logic Modules, and Linear Gates are used in many research or teaching experiments and in non-research applications such as actively shielded spectroscopy systems. Delay modules allow the alignment in time of signals from different paths, so that a logical decision can be made within a logic module which will often result in an electronic go/no-go decision as to whether a particular detector analog output will be processed within an associated multichannel analyzer.

ORTEC offers a broad range of NIM Delays, Gate and Delay Generators, Logic Modules, and Linear Gates.

​CO4020 Quad 4 Input Logic Unit
DB463 Delay Box
GG8020 Octal Gate and Delay Generator
414A Fast Coincidence
416A Gate and Delay Generator
418A Universal Coincidence
425A Nanosecond Delay
426 Linear Gate
499 Fast Slow NIM Logic Converter
542 Linear Gate and Stretcher

Cables and Accessories

​​Blank NIM Modules - Models 400A, 400B, and 400C

Blank Panels - Models 400-1B, 400-2B, and 400-3B

Signal Splitter - Model MT050

Magnetic Shield - Model 218

Cable Assemblies, Bulk Cable and Custom Cable Assemblies



​Bulkhead Mounted Jacks



​EtherNIM 10Base2 to 10BaseT Adapter Kit (BNC to RJ45) - Model ETHRJ45

​USB Accessories

Photomultiplier Tube (PMT) Bases

​Scintillation detectors produce light as they absorb energy, and these light flashes result in the release of a proportionate number of photoelectrons at the cathode of a photomultiplier tube (PMT). Each of the ORTEC Photomultiplier Tube Bases is designed to accommodate a particular type of PMT to distribute the operating voltages to all its elements, and to derive signals from it.

Classically, high voltage has been supplied to the PMT base from an external supply. More recently the supply was integrated into the base itself and now even the multichannel analyzer is integrated within the PMT base. Models of all of these types are available from ORTEC.

​265A Photomultiplier Base
266 Photomultiplier Base
269 Photomultiplier Base
276 Photomultiplier Base with Preamplifier
276L Low Power Photomultiplier Base
296 ScintiPack Photomultiplier Base with Preamplifier and HV Supply
DigiBASE 14-Pin PMT Base with Integrated Bias Supply, Preamplifier, and MCA (with Digital Signal Processing)
DigiBASE-E High Performance, Digital Gamma Spectrometer


​The primary function of a preamplifier is to extract the signal from the detector without significantly degrading the intrinsic signal-to noise ratio. Three basic types of preamplifiers are available: the current-sensitive preamplifier, the parasitic-capacitance preamplifier, and the charge-sensitive preamplifier. ORTEC manufactures a preamplifier to fit your detector, your application, and your budget.

​113 Scintillation Preamplifier
142A/B/C Preamplifier
142AH Preamplifier
142IH Preamplifier
142PC Preamplifier
276 Photomultiplier Base with Preamplifier
296 ScintiPack Photomultiplier Base with Preamplifier and HV Supply
9301 Fast Preamplifier
9305 Fast Preamplifier
9306 1-GHz Preamplifier
9326 Fast Preamplifier
FTA820A Octal Fast Timing Amplifier
VT120 Fast Timing Preamplifier

Counters, Timers, Rate Meters, and MCS: Single and Multiple Input, 
Fast and Slow Logic

​​ORTEC offers the broadest range of nuclear counters, timers, rate meters and multichannel scalers. Counters simply count the number of input pulses received during the counting period. Timers count pulses generated by an internal or external clock and are used to measure elapsed time, or to establish the length of the counting period. Rate meters provide a readout of the pulse count rate. Multichannel scalers count the number of events that occur during a specified time interval, referred to as the dwell time, resulting in a time-histogram of counts. “Standalone” and programmable computer controlled versions are available.

​449/449-2 Log/Lin Rate Meter
661 Rate Meter
871 Timer and Counter
928 High Performance, Multi-Function MCA/Counter/Timer/Rate Meter
974A CCNIM Quad 100-MHz Counter Timer
976 Quad 250-MHz Counter Timer
978 Dual Timer
994 Dual Counter and Timer
995 Dual Counter Data Sheet
996 CCNIM Timer and Counter
9349 Log/Lin Rate Meter
EASY-MCS Multichannel Scaler