The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 26, 1991
Filed:
Apr. 17, 1990
Eiichi Tanaka, Shizuoka, JP;
Tatsuro Hayashi, Shizuoka, JP;
Hamamatsu Photonics K.K., Shizuoka, JP;
Abstract
An ionization chamber can stably measure a weak ionizing radiation with high sensitivity. The ionization chamber comprises an electrically conductive charge collecting electrode having a magnetic substance or a permanent magnet; an electromagnet for positioning the charge collecting electrode in non-contact with the other part of the ionization chamber; a position sensor for detecting the position of the charge collecting electrode; a circuit for feedback-controlling the magnetic force of the electromagnet to maintain the charge collecting electrode at the substantially same position; and ionization current detecting circuit for detecting an ionization current collected at the charge collecting electrode by ionization due to radiation applied to the ionization chamber.