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Re: sparks

According to the EB, the field strength for electrical breakdown of air at
atmospheric pressure is 10,000 V/cm. Within thunderclouds, fields of 1000
V/cm are exceeded only over limited areas. This information is also
available in the CRC Handbook in the spark gap section.

At 5:46 AM -0800 2/18/2001, John S. Denker wrote:
At 02:23 AM 2/18/01 -0800, Bernard G. Cleyet was skeptical of my guestimate
of the breakdown field:
It's about 3 megavolts per meter. You can guestimate this answer based on
the previously-described model: an ion needs to pick up enough energy
between collisions to have a fair chance of ionizing whatever it
hits. That requires a field strength on the order of a fraction of a volt
per mean-free-path.

Dr. Lawrence D. Woolf; General Atomics, 3550 General Atomics Court, Mail
Stop 15-242, San Diego, CA 92121