View PDF Catalog   

Closeout Items   

PTW 34045, Advanced Markus Electron Chamber

PTW 34045, Advanced Markus Electron Chamber
PTW 34045, Advanced Markus Electron Chamber

Item Number :

PTW 34045, Advanced Markus® Electron Chamber.


Open Section E: Cables, Connectors, Chambers, Stands & Accessories(PDF) to view related products. (Opens in a new tab)

PTW 34045, Advanced Markus® Electron Chamber.

The Advanced Markus features a wide guard ring design to avoid perturbation effects by reducing the influence of scattered radiation from the housing.  Since the outer shape is identical with the Markus chamber, all existing Markus chamber phantom plates and adapters can be used with the Advanced Markus chamber.  The small sensitive volume makes the chamber ideal for dose distribution measurements in a water phantom, giving a good spatial resolution.  The chamber features a flat energy response within the nominal energy range from 2 MeV to 45 MeV.  With the very thin membrane of only 0.03 mm polyethylene, the chamber is suitable for use in solid state phantoms.  The chamber comes with a protective acrylic cover of 0.87 mm thickness (1 mm water equivalence) for use in water.  A calibration certificate with a 60Co calibration factor given in absorbed dose to water is included.  Air density correction is required for each measurement.  The chamber cable length is 1.05 m.

• Perturbation-free electron chamber

• Thin entrance window and waterproof protection cap

• Small-sized for high spatial resolution

• Sensitive volume 0.02 cm3, vented to air

• Suitable for relative and absolute electron dosimetry

Perturbation-free version of the famous classic Markus chamber for absolute dosimetry in high-energy electron beams.


Type of Product:  vented plane parallel ionization chamber
Application:  absolute dosimetry in high-energy electron beams
Measuring Quantities:  absorbed dose to water
Reference Radiation Quality:  60Co
Nominal Sensitive Volume:  0.02 cm3
Design:  Waterproof with protection cap, vented
Reference Point:  in chamber center on entrance foil, or 1.3 mm below surface of protection cap
Direction of Incidence:  perpendicular to chamber plane
Nominal Response:  0.67 nC/Gy
Long-term Stability:  ≤ 1% per year
Chamber Voltage:  300 V nominal ±400 V maximal
Polarity Effect:  ≤ 1% for electrons ≤ 9 MeV
Directional Response in Water:  ≤± 0.1% for chamber tilting ≤± 10°
Leakage Current:  ≤ ± 4 fA
Cable Leakage:  ≤ 1 pC/(Gy∙cm)

Materials and Measures: 
Entrance foil:  0.03 mm PE (polyethylene CH2), 2.76 mg/cm2
Protection cap:  0.87 mm PMMA, 1.19 g/cm3, 0.4 mm air
Total window area density:  106 mg/cm2, 1.3 mm (protection cap included)
Water-equivalent window thickness:  1.06 mm (protection cap included)
Sensitive Volume:  radius 2.5 mm depth 1 mm
Guard ring width:  2 mm

Ion Collection Efficiency at Nominal Voltage: 
Ion collection time:  22 µs

Max. dose rate for:
> 99.5 % saturation:
  187 Gy/s
> 99.0 % saturation:  375 Gy/s

Max. dose per pulse for:
> 99.5 % saturation:
  2.78 mGy
> 99.0 % saturation:  5.56 mGy

Useful ranges: 
Chamber voltage:  ±50 to 300 V
Radiation quality:  2 - 45 MeV electrons
Field size:  3 x 3 cm2 to 40 x 40 cm2
Temperature:  50° - 104° F (10° - 40°C)
Humidity:  10 - 80 %, max 20 g/m3
Air pressure:  700 - 1060 hPa


Please specify which connection end is needed

Data Sheet