PTW Farmer®
Ionization Chambers
PTW Farmer® ionization chambers conform to the physical dimensions and meet or exceed the performance standards of the original Farmer® design. They are available from CNMC in several configurations. All chambers feature a new, low-noise triaxial cable with radiation resistant insulation. Each chamber is supplied with an integral 1 meter cable, male triax BNC connector with cap & chain, an acrylic 60Co buildup cap and a foam-lined case.
N30010 - 0.6cm3, acrylic/graphite
Model N30010 (formerly N30001, formerly N23333) with a sensitive volume of 0.6cm3, features a thimble with internal 0.09mm thick graphite layer, protected by a 0.335mm acrylic exterior wall. This combination makes the N30010 essentially air-equivalent with all the ruggedness of an acrylic thimble.
N30012 - 0.6cm3, graphite
Model N30012 (formerly N30004) has a sensitive volume of 0.6cm3, with a thimble that is made entirely of graphite, but with an aluminum central electrode for enhanced low-energy response uniformity.
N30012.2 - 0.2cm3, graphite
Model N30012.2 (formerly Model N30004.2) is a CNMC version of the model N30004 with a sensitive volume of 0.2cm3 for greater spatial resolution, an all-graphite thimble and aluminum central electrode. It is supplied with an appropriate acrylic 60Co buildup cap. Optional 15mm long acrylic spacers to take up the extra space within a solid phantom drilled for 0.6cm3 chambers are available.