The measurement of charge response of powders exposed to ion bombardment

✍ Scribed by Lowell W. Zabel; Allan R. Estcourt

• Book ID: 101579718
• Publisher: John Wiley and Sons
• Year: 1969
• Tongue: English
• Weight: 495 KB
• Volume: 13
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1969.070130910

✦ Synopsis

A system has been designed and developed to subject a sample of powder on a grounded metal plate to charging by ion bombardment and to measure the charge accepted by the sample.

A method of sample preparation was evolved which made it possible to obtain samples of known particle size and number of particles. The sensitivity of measurement and the noise levels were investigated and found to be acceptable. Calibration tests were made to determine the validity of the proposed equation relating the measured voltage, circuit capacitances, and the ratio of probe height to net charge location. It w & ~ found that for a wide range of values of the ratio of probe height to particle diameter, the linear equation was a good description of the process and could be used to accurately determine the charge on a sample. Some measurements were made on typical powders to illustrate the feasibility of the method and equipment to characterize variable charging properties.

Observation of the charge decay from the sample was also possible.