Exradin A1 Ion Chamber

Proven guard design yields stable, precise measurements and minimizes settling time by creating uniform field lines
Shell, collector, and guard are all made of durable, long lasting Shonka conductive plastic
Use of homogeneous material throughout the chamber minimizes perturbation of the beam due to the presence of the chamber and optimizes measurements
Axially symmetric design of the chamber provides an uniform, isotropic response
Inherent waterproof construction eliminates need for additional protective coverings
Two separate stem pieces of 5.1 cm and 12.7 cm can be coupled together for ease of use
Additional build-up caps of C552, A150, Delrin, and brass are available
Ionization collection efficiency is always 99.9% or better
Small collection volume allows for optimal spatial resolution and exact characterization of a small area of the beam in depth-dose measurements
Collecting volume is 0.057 cc

UNCOMPROMISING QUALITY

For relative dosimetry scanning and measuring points in water, air, or other phantom material

A PERFECT BALANCE BETWEEN FAST SCANNING AND POINT DOSE MEASUREMENTS

The Exradin Miniature Shonka Thimble Chamber provides a perfect balance between fast scanning and point dose measurements within 1 cm in water, air, or other phantom material. Model A1, REF 92705 is completely characterized in TG 51 and TRS 398.

FAST, PRECISE MEASUREMENTS

The chamber features exceptional spatial resolution for relative dosimetry scanning and is capable of measuring small field sizes of 6 mm by 8 mm for accurate point dose measurements. Its waterproof construction and two piece removable stem makes it ideal for use in water phantoms. The chamber vents through a flexible tube that surrounds the triaxial cable, ensuring the collecting volume is in pressure equilibrium with the surroundings. The design assures there are no stem or voltage soakage effects, providing precise and reliable measurements.

DURABLE CONSTRUCTION, BUILT TO LAST

The Model 1 Exradin Miniature Shonka Thimble Chamber is offered in two versions of rugged, Shonka plastic, providing excellent conductivity and years of reliable use:

C552 Shonka air-equivalent plastic, Model A1, REF 92705
A150 Shonka tissue-equivalent plastic, Model T1, REF 92706

Specifications

REF Number	92705 - Model A1 92706 - Model T1
Collecting Volume	0.057 cm³
Nominal Calibration Factor	60 R/nC
Centroid of Collecting Volume	4.0 mm from tip of chamber
Collector Diameter	1.0 mm
Outside Diameter of Shell Collecting Volume	6.0 mm
Wall Thickness	1.0 mm
Shell, Collector, and Guard Material	A1 - Shonka air-equivalent plastic C552 T1 - Shonka tissue-equivalent plastic A150
Venting	Vented to the ambient via the flexible vent tube surrounding the triaxial cable
Stem	1.3 cm OD black phenolic, two-piece with 5.1 and 12.7 cm segments
Nominal Collection Efficiency	1.000
Maximum Polarizing Potential	1000 V
Nominal Inherent Leakage Currents	10^-15 A
Low-Noise Triaxial Cable	50 ohms, 29 pF/ft, 1.5 m long
Signal Connector	Triaxial BNC plug (2-Lug, male pin); others available upon request
High Voltage Connector	Integral with triaxial connector (shell of chamber is common with connector body)
Waterproof	Yes
Product Standards	CE₀₄₁₃, Designed to meet IEC 60601-1, IEC 60731

Model 1 Schematic