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ULTRA and ULTRA-AS Ion Implanted Detectors for Alpha Spectroscopy

Both the input and the back contact are implanted with ions. The input contact is an extremely thin (~500 Å) boron implantation. The distance between the silicone surface and the top of the mounting can is <1mm, providing maximum geometric efficiency. The front contact can be easily cleaned with a cotton swab moistened with solvent.


ULTRA detectors have gold plated mounting tabs. Gold's superior electrical conductivity, which can never rust, makes it a better choice than stainless steel or aluminum. An advanced surface passivation covering the critical silicon dioxide layer ensures absolute device stability. Extremely low leakage current allows energy resolution to be specified at an amplifier setup time constant of 1 µs.


ULTRA-AS low background detectors are made from special low background materials and have an optimized depletion thickness to minimize cosmic ray background counts. All ORTEC Alpha spectrometers (Alpha Aria, Alpha Duo and Alpha Ensemble) can be equipped with ULTRA-AS detectors or R-series ruggedized surface barrier detectors. All of these spectrometers, when equipped with a 450 mm 2 detector, have a Guaranteed background performance of ≤24 counts per day, in the energy range of 3 to 8 MeV.


The mounting tab dimensions of the ULTRA and ULTRA-AS detectors, which are identical to those of the correspondingly sized A or R series detectors, ensure that the ULTRA detectors will fit perfectly into any application in which they are now used. A or R series detectors.



  • The standard for charged particle detection spectroscopy.
  • Ultra-thin input contact for optimal energy resolution.
  • High geometric efficiency due to the narrow gap between the detector and the can.
  • Robust and reliable.
  • Gold-plated tins for contacts that last a lifetime.
  • Advanced surface passivation for full device stability.
  • ORTEC quality and reliability.
  • Bakeable up to 200°C (requires special order).



  • Low background version for alpha spectroscopy.
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