Topaz HR Multi-Channel Analyzer


Introduced March 2018, Topaz-HR is a compact stand-alone MCA for high-resolution detectors such as Hyper Pure Germanium Detectors (HP-Ge).

Topaz-HR is a compact, stand-alone digital Multi-Channel Analyzer (MCA), which is able to perform a Pulse Height Analysis (PHA) of the signal produced by high resolution gamma-ray semiconductor detectors, such as Hyper-Pure Germanium Detectors (HPGe). These detectors are commonly used in high-resolution gamma-ray spectrometry, an analysis method extensively used by advanced radio-analytical laboratories as part of comprehensive nuclear analytical methods. The Topaz-HR MCA can also be used with detectors with lesser energy resolution, such as scintillators like NaI (Tl), LaBr3, CeBr3, etc.

The Topaz-HR is supplied with a basic software package that allows the user to control the device, and to acquire and visualize the energy spectrum. The software incorporates an advanced and easy-to-use “discovery” function that can be used to detect automatically all BrightSpec-built MCAs that are physically connected to the PC or in the immediate network neighborhood. Alternatively, the MCA is offered with our full-featured, advanced Gamma-ray spectrometry software package - bGamma. This software allows the user to perform data acquisition and spectrum analysis within the same software framework, including all necessary calibrations, and radioactivity quantization per radionuclide in the sample.

A set of programming libraries is also available, which makes the incorporation of the Topaz-HR into existing radiation systems or setups very easy. The programming libraries are available for MS Windows, Linux and Mac operating systems.

Download the full specification sheet


Main Features

  • 14-bit high performance ADC, sampling rate of 50 Ms/s
  • 100MHz DSP processor
  • Up to 16K channels with a depth of 32 bits
  • Supports both RC and pulse-reset type of pre-amplifiers
  • Data acquisition modes: PHA, MCS, LIST mode and TLIST mode
  • Data acquisition: by present time value (real or live), by counts (in ROI) and by an external control signal (or a combination of these three)
  • Trapezoidal pulse shaper
  • Dead time correction with fine-tuning capability
  • HV power supply: 0V to 6000V, 350 µA with automatic ramping. Dual polarity, but fixed at factory
  • Preamplifier power supply: ±24V @ 125mA and ±12V @ 125mA
  • Two user-programmable I/O lines that can be used as external counters, external data acquisition, etc.
  • High-speed USB 2.0, up to 480 Mbit/s
  • Lightweight and small: 126 x 106 x 56mm [5 x 4.17 x 2.2] (L x W x H) 
  • Full-featured Gamma-ray spectrometry software bGamma, at package cost



The Topaz-HR is an advanced, fully digital, compact Multi-Channel Analyzer. This device is used to process the electronic pulses typically produced by high-resolution semiconductor detectors such as Hyper-Pure germanium detectors (HPGe). However, the MCA can also be connected to other types of detectors, including scintillators (e.g. NaI(Tl), CeBr3 or LaBr3, etc.), which makes it a valuable and multi-purpose device, a “must have” in your lab.

The MCA implements several advanced modes of data acquisition: Pulse Height Analysis (PHA), Multi-channel scaling (MCS), LIST and Timestamped-LIST mode (TLIST). For the latter, each recorded pulse is stored with the arrival time stamp in addition to the pulse height information (energy). In TLIST mode the event time resolution is better than 30 nano-seconds. The Topaz-HR design incorporates the latest advances in digital electronics, the core of the MCA is its 14-bit high-quality fast flash ADC running at 50 Ms/s, a 100 MHz DSP processor and a 200 MHz CPU. The device has a spectral memory of up to 16 384 (16K) channels of 32-bit depth available for any acquisition mode.

The device includes a low-noise High Voltage bias supply which is able to generate an output from 0 to 6000 Volts, as well as a low voltage supply (±24 and ±12 Volts) intended to power the most commonly found pre-amplifiers via a standard DB9 connector.

The Topaz-HR transfers acquired data via a high speed USB connection to the PC with data transfer rates of 480 Mbit/sec. The MCA is powered using an external low-noise AC/DC power supply, which is included in the delivered package. The MCA is encased into a rugged aluminum box with all the necessary connectors for the detector and auxiliary signals, plus one USB (mini-B) for the PC. In the front panel several LEDs signalize the status of the device and data acquisition.

The device can be controlled with a basic acquisition software (bMCA software), which is freely downloaded from the BrightSpec Website. Alternatively, the MCA control is incorporated into our fully-featured Gamma-ray spectrometry analysis software— bGamma. An attractive package price can be obtained when ordering the MCA together with bGamma software. The programming libraries for Windows®, Linux™ and macOS are available as well.


Technical Specifications


    • 14-bit high-performance flash ADC, 50 Ms/s sampling rate.
    • 100 MHz DSP processor.

Data Acquisition

    • Spectral memory sizes of 256, 512, 1024, 2048, 4096, 8192 and 16 384 (16K) channels of 32-bits depth.
    • Supports both RC and pulse-reset type of Pre-Amplifiers.
    • Acquisition modes : PHA, MCS, LIST mode and TLIST mode.
      • LIST and TLIST modes with better than 30 nsec event time resolution.
    • Analog gain from x1 to x256. Coarse gain with amplification factors of 1, 2, 4, 8, 16, 32, 64 and 128. Fine gain from 1 to 2 in steps of 1/16384 (~ 0.000061)
    • Upper and Lower Level Discriminator settings given in channels.
    • Automatic reset pulse detection or via external signal.
    • Preset acquisition times from 0.005 seconds to approx. 0.65 years.
    • Built-in several preset acquisition modes:
      • By preset time value (real or live times)
      • By counts (in ROI)
      • By external control signal or
      • Combination of any above


    • Spectral memory sizes of 256, 512, 1024, 2048, 4096, 8192 and 16384 channels, depth 32-bits.
    • Dwell time from 0.005 seconds to "count-forever”.

    Digital Settings

      • Trapezoidal pulse shaper.
      • Rise Time: from 0.1 to 12 ms in steps of 0.2 m
      • Flat Top: from 0.1 to 8.0 ms in steps of 0.1 m
      • Adjustable Fast discriminator threshold.
      • Digital Base Line Restorer (BLR).
      • Pile-Up Rejector (PUR).
      • Analog and adjustable Poles/Zero cancellation correction.
      • Dead time correction with fine-tuning capability.

      Power Supply

        • Device power by external low-noise AC/DC power adaptor 9-24V (supplied), 15W max.
        • Preamplifier power supply: +- 24 V @ 125 mA and +-12V @ 250 mA.
        • HV power supply: 0 to 6000 V, 350 mA with automatic ramping. Dual polarity, but fixed at factory.
        • External HV Inhibit control.


          • Two user-programmable I/O lines.
          • Can be used as external counters, external data acquisition control, etc.

        Data Communication

          • High-speed USB 2.0, up to 480 Mbit/s.
          • Standard 3-meter long USB cable supplied. Physical
          • MCA box: length 126 mm, width 106 mm, height 56 mm.
          • Weight: less than 200 grams (including box).
          • Connectors :
            • Front: EXT DC barrel-type, USB mini-B.
            • Back: SHV for high voltage output, 3x BNC for signal and GPIO, DB9 connector for preamplifier power.
          • Indicators:
            • Red LED for detector high voltage status.
            • Yellow LED for incoming count rate (ICR).
            • Green color LED for power and communication status.
            • Read and Yellow LED blink synchronously in case of HV fault.


          • The device is supplied with a basic software to control operation, data acquisition and visualization.
          • Upon request: set of programming libraries for Microsoft Windows® and Linux.


          • The MCA can be supplied with the full-featured Gamma-ray spectrometry software—bGAMMA, at an attractive combined package price.


          • The device is CE compliant.

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