ABSTRACT

TRANSIT-TIME METHOD FOR ESTIMATING AIR-ION CONCENTRATIONS

William T. Kaune

TABLE OF CONTENTS

I. Introduction 58

II. Theoretical Methods 58 A. Transit-Time Method 58 B. Upper Bound on Space-Charge Densities 61

III. Selected Applications 62 A. Analysis of Symmetrical Systems 62 B. Generation of Space Charge in a Room 64 C. Decay of Space Charge in Ducts 64 D. Evaluation of Published Space-Charge Data 64

1. Air Ion Exposure Chamber Used by Terry et al 65 2. Air Ion Exposure Chamber Used by Krueger, Andriese,

and Kotaka 65 E. HVdc Transmission Lines 65

IV. Discussion 68

Acknowledgments 68

References 68

I. INTRODUCTION

A small fraction of the molecules and particles in atmospheric air are electrically charged.' Considerable research has been performed to determine if changes in concentrations of these air ions can affect living organisms.' Recent measurements have shown that air-ion concentrations are significantly increased in the vicinity of high-voltage direct-current (HVdc) electric-power transmission lines." Concerns about possible health effects to humans or animals working or living near these lines have resulted in a much more critical scrutiny of past research results and the initiation of new projects to determine whether exposure to air ions produces biological effects.