Abstract
This paper describes an experimental investigation of the charge acquired by a single particle when striking a metal plate. The particle was projected from a pneumatic gun onto the metal plate. The initial charge carried on the particle before impact and impact charge were measured under various conditions of impact velocity, νο (7∼18 m/s) and angle, θ (0º∼60º).
The charge transfer is dependent not only on the impact conditions but also on the initial charge of the particle. The impact charge almost proportionally decreases with an increase in the initial charge. There is a particular value of this charge which results in no net transfer and which is independent on the impact conditions. This special point can be utilized to estimate the effective work function of insulating particles.
While a larger impact velocity leads to a larger charge transfer because in the increase of the contact area, the data cannot be arranged with the maximum contact area derived from the normal component of the impact velocity, νοcosθ. A much larger enhancement of the charge transfer is caused by the tangential component of velocity, νοsinθ. This fact is extremely different from the previous works (Refs. 2 and 4) which describe that the tangential component had no effect on the charge transfer by collision.
† This report was originally printed in J. Soc. Powder Technology, Japan. 24(12), 765-770 (1987) in Japanese, before being translated into English by KONA Editorial Committee with the permission of the editorial committee of the Soc. Powder Technology, Japan.
