Discharge Electroscope with Alpha Source

Modern Physics > Nuclear Physics > Radioactivity

DCS# 5D40.30

DISCHARGE OF AN ELECTROSCOPE WITH AN ALPHA SOURCE

APPARATUS

Am-241 from smoke detector	015B-lead cabinet
two gold leaf electroscopes	202-18-C
fur and rubber rod	202-18-D5, 6
camera	202-09-D

DESCRIPTION

Charge both electroscopes with the charged rubber rod. Bring the alpha source near one electroscope and it will discharge more rapidly than the other. The alpha source ionizes the air and the ions neutralize the electroscope. The effect is clear but not dramatic - it takes about a minute to discharge the electroscope on a dry day. The second electroscope is for comparison.