120 Pixel Ion Chamber


  • 42mm diameter sensitive area
  • Low insertion length 20mm face to face
  • 120 pixels with parallel readout
  • Ultra-low scattering thin film electrodes
  • Negligible beam scattering
  • HV loopback
  • Operates in air or with flow-through gas mixtures
  • Compatible with I128 and I6400 electrometers


  • Particle therapy pre-scan beam monitoring
  • Particle therapy "IC1" upgrades
  • General high energy ion beam diagnostics


  • Compatible with protons, deuterons, and fully-stripped carbon
  • Energy range 30MeV/nucleon to 500MeV/nucleon
  • Gain uniformity better than +/-2% for beams within the sensitive area
  • Position linearity better than 50µm maximum deviation
  • Tolerance relative to body fiducials < +/-0.1mm typical, +/-0.3mm max

Pixelated Detector

Pixelated detectors offer many advantages over strip detectors as they are capable of determining beam shape without ambiguity.

  • High precision pixels on gold film provide excellent reliability
  • Fine resolution data enable confidence in beam quality
  • Compliments the strengths of the gamma index

Integrated Environment Sensors

Our ion chambers include integrated sensors for environmental corrections. No need for costly and inconvenient external instruments.

  • Humidity sensor
  • Temperature sensor
  • Pressure sesnor
  • Replacable desiccant

Expertly Built

Electrodes patterned with unique laser technology. Assembled and tested by highly skilled technicians in our dedicated assembly facility.

  • Rigorously tested beyond normal operating range to ensure uniformity
  • Envirmonmental sensor measured against externally calibrated sources
  • Each ion chamber is fully retested after it has been opened
  • Real calibrated radioactive source is used as reference
  • Full test documentation can be provided for each individual instrument

Ion Chambers

The ionization chamber or ion chamber is conceptually the simplest of all gas-filled radiation detectors, and is widely used for the detection and measurement of ionizing radiation. It is the preferred device for proton therapy dose and beam position monitoring due to a combination of robustness, gain stability, very low material budget in the beam path and availability of large continuous sensing areas.

Pyramid offers a wide range of ionization chambers for proton and heavy ion therapy applications. Advanced electrode coating and patterning allows the creation of precise strip and pixel patterns for position readout. A wide range of sensitive areas and electrode gaps is provided to suit different system geometries and beam currents.

Proton Therapy

Proton therapy is well established for the treatment of localized cancer tumors, especially when there are vital organs close by. This healthy tissue sparing makes it the method of choice for maintaining quality of life and especially for treating children. The proton beam delivery is fast and painless.

Proton therapy centers worldwide use Pyramid sensors, electronics, and software. Pyramid offers products for complete systems, sub-systems, or components. For more information see our Pencil Beam Scanning Brochure