Theory of Operation
Introduction 3
Section 3
Theory of Operation
3.1 Introduction
The Model 90100 TRACKER System is a radiation measurement system intended for use in quality assurance programs for high-energy accelerators and Co60. The two main components of the system are the Model 35300A Detector and the Model 35360A TRACKER Display. This section describes the basic theory of operation of these devices. For more information regarding radiation dosimetry and ion chamber measurement theory, the reader should refer to one of the standard radiology physics texts.
The section begins with a simplified hardware block diagram of the Model 35360A Display accompanied by a short description of the most important blocks. Next follows a short description of the Model 35300A Detector and a discussion of air density corrections. The section concludes with a description of the system's basic operating parameters and equations.
3.2Overall Functional Description of the Model 35360A TRACKER Display
The 35360A TRACKER Display contains a five-channel electrometer capable of producing measurements of dose and dose rate. Its 4 line by 20 character vacuum fluorescent display (VFD) can display the measurement results directly in the user's choice of radiological units. These readings may include air density corrections if desired. An integrated rechargeable battery and a 300 V electronic bias supply greatly simplify maintenance of the system. The 35360A TRACKER Display includes an RS-232 serial communication port that allows complete computer control of the measurement system. This communications port, in conjunction with internal non-volatile memory, also provides a means of customization and calibration of the 35360A TRACKER Display.
Figure 3-1 is a simplified hardware function block diagram for the 35360A TRACKER Display. While the most important interblock connections have been shown, many interconnections have been omitted in order to maintain clarity. Three external connections are illustrated. These are the AC Line, the RS-232 Computer Interface, and the Detector Input.
