Re: The Paschen Curves & Pseudospark Switches

[Frederick Sparber]

Notice the P*D minimum for air at the pressure where the Crookes Radiometer

works best,

 

Fred

 

http://www.duniway.com/images/pdf/pg/Paschen-Curve.pdf

 

 

----- Original Message -----

From: Frederick Sparber

To: vortex-l

Sent: 5/3/2006 12:57:42 PM

Subject: Re: The Paschen Curves & Pseudospark Switches

Is there something else involving pressure going on here too?

 

http://empl.ksc.nasa.gov/CurrentResearch/Breakdown/Breakdown.htm

 

"Paschen measurements are taken which relate the minimum potential required to spark across a gap between two electrodes. The minimum potential is plotted versus the pressure-distance value for electrodes of a given geometry. For most gases, the potential decreases as the pressure decreases. For CO2, the minimum in the curve happens to be at Mars atmospheric pressures (5-7 mm Hg) for many distances and geometries. However, a very small amount (<0.1%) of mixing gases radically changes the curve, as noted by Leach. Here, ! ! we present the first experimental results of a Paschen curve for a Mars gas mixture compared with 100% pure CO2."

 

Thus the electrodes fixed at 0.1 cm apart provided the parallelplate geometry.

The chamber was pumped down to 104 mm Hg and backfilled to ~ 50 mm Hg with the atmospheric gas. It was pumped down again to remove residual gases and contaminants. The gases that were used are 100% CO2 and a Mars gas mixture provided by Praxair Inc. that consisted of 95.5% carbon dioxide, 2.7% nitrogen, 1.6% argon, 0.13% oxygen and 0.07% carbon monoxide.

 

Leach's Curves:

 

http://empl.ksc.nasa.gov/CurrentResearch/Breakdown/Leach.htm

 

Pseudospark Switches:

 

http://users.tm.net/lapointe/Pseudospark_Switches.html