RE: Radon class demo

[Rick_Strickert@radian.com]

Another active way to get a sample of radon daughters was demonstrated in an
article, "Radioactiveball", by James Cowie, Jr. and Thomas Walkiewicz (_The
Physics Teacher_, Vol.30, Jan. 1992, pp. 16-17).  According to Cowie and
Walkiewicz, "a group of senior faculty members at Edinboro University of
Pennsylvania played handball as vigorously as they could for 50 minutes."
Starting three minutes after the end of the game, a thin -walled G-M tube
and scaler was used to monitor the (primarily beta) activity of the ball.
The initial activity was 550 cts/ 5 min. and the experimental 'effective'
half-life was 43.9 +/- 1.2 min.

The authors also noted that a racquetball used by several groups of students
gave an initial activity after 20 minutes of almost 1200 cts/ 5 min.
Humidity, indoor/outdoor location, and amount of use (with a not-too-subtle
reference to the relative ages of the athletes :-)) were considered as
factors in capturing radon daughter activity.  The authors suggested that
balls from different sports might be tried for activity measurements.

Rick

Richard G. Strickert, Ph.D.
Radian International
P.O. Box 201088  Austin, TX 78720
14046 Summit Park,  Austin, TX 78728
512-310-5259 (Phone)
512-244-0160 (Fax)
rick_strickert@radian.com <mailto:rick_strickert@radian.com> 

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