ELECTRONIC EQUILIBRIUM IN FREE-AIR CHAMBERS AND A PROPOSED NEW CHAMBER DESIGN. Interim Report

Technical Report · Thu May 18 04:00:00 EDT 1961

OSTI ID:4822262

Attix, F H

The concept of electronic equilibrium, particularly as applied to free- air chambers, has been frequently used to cover more than one idea, In order to separate and define clearly each idea, definitions are established for integral charged-particle equilibrium'' and charged-particle compensation.'' In addition, a definition for chargedparticle equilibrium'' is proposed along the lines set forth by Roesch, A new type of free-air ionization chamber is proposed in which electric-field uniformity plays no role in defining the ion-collecting volume. The chamber is based essentially upon a subtraction method in which two readings are taken of the ionization and the difference is used as a measure of exposure dose. The chamber is collapsible, its midplane being fixed with respect to the x ray source. The ionization in the two equal air volumes on either side of the midplane of the chamber when in a collapsed condition and the ionization of the two volumes defined by the chamber in an expanded condition are related in such a way that their difference is just the ionization in the extra volume of air created in the middle of the chamber by the expansion of the chamber. It is evident that the end planes of this extra volume of air are not defined by electrostatic lines of force, as is the case for con ventional chambers. Consequently, the new chamber has no need for guard plates or other fieldshaping electrodes which are typical of conventional free-air chambers. Since the uncertainty about the degree of field uniformity represents the largest single source of error in conventional chambers, its elimination is a considerable advantage. (auth)

• Research Organization: Naval Research Lab., Washington, D.C.
• NSA Number: NSA-16-017821
• OSTI ID: 4822262
• Report Number(s): NRL-5646
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AIR
CHARGED PARTICLES
ELECTRIC FIELDS
ELECTRODES
ELECTRONS
ELECTROSTATICS
ENGINEERING AND EQUIPMENT
ERRORS
IONIZATION CHAMBERS
PLANNING
PLATES
RADIATION DETECTORS
RADIATION DOSES
RADIATION SOURCES
X RADIATION