Innovation and Partnerships Office

Active Microphonic Noise Cancellation in Radiation Detectors IB-2013-038

APPLICATIONS OF TECHNOLOGY:

  • Radiation detection for the nuclear power and other industries

ADVANTAGES:

  • Improved performance
  • Adapts to the detector’s environment
  • No advance knowledge of vibration sources and characteristics required

ABSTRACT:

Berkeley Lab researcher Sergio Zimmermann has developed a new technology to improve energy, timing, position, and tracking resolution in radiation detectors by electronically reducing microphonics without using mechanical compensation.

The Berkeley Lab innovation uses filtering to reduce microphonic noise, based on system identification that cancels the noise. Specifically, a sensor measures mechanical disturbances that cause vibration on the detector assembly, and a digital filtering estimates the impact of these disturbances on the microphonic noise. The noise can then be subtracted from the detector measurement.

Microphonics inject charge into a radiation detector and degrade its performance. Sources for such mechanical disturbances include nearby vacuum pumps, cryocoolers, nitrogen “bubbling,” and even audible noise in the detectors’ vicinity. Current efforts to reduce microphonics include the use of very rigid structures that permit little vibration; decoupling of the detector from the structure’s frame; filters; counterweights to compensate the vibration; and other approaches. Such strategies assume a priori knowledge of the vibrations or amplification system. Vibrations can have differing characteristics, depending on their source, and they can change with time and orientation of the detector. Berkeley Lab’s new technology can adapt to new sources or modes of vibration, leading to general microphonics cancellation in several detector conditions and uses.

DEVELOPMENT STAGE: Model testing yielded approximately 95% improvement in microphonics cancellation.

STATUS: Patent pending. Available for licensing or collaborative research.

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

More Sensitive, Less Expensive Semiconductor Detectors, IB-2607

Neutron Detection Technique Using Layered Semiconductors, IB-2424

REFERENCE NUMBER: 2013-038