Recent content by Charles Link

Happy Groundhog Day 2-2-26. The above is a photo of the snowman that I have in my backyard. It now measures about one inch over 4'0". It has been there for over two weeks. It did not see its shadow today in Chicago. Let's hope winter is almost over. :)

The above is a photo of a 4'8" snowman that I made today, Friday 1-16-26, in Chicago. The snow was too cold to pack this morning with temperatures below freezing, but around noon it warmed up to 37 degrees and packing conditions were ideal.

Thank you @Greg Bernhardt and all who voted for me. I am honored.:smile:

It would be interesting to know the voltages in the bulb in this Princeton paper. I don't have access to the paper.

I think the potentiometer might be a ballast resistor (in series with the supply voltage and plasma material) with a resistance that can be varied. If that is the case, characterizing the voltage could be difficult, because the plasma behaves so non-linearly, where the voltage through the...

We lost a great member. I will miss him.

I'm more familiar with arc lamps running at higher currents and low voltages. When they operate at high voltage, the currents will be very small. The lamps that operate at low voltages normally need a higher voltage to start the arc, unless thermionic emission is employed with a heated...

Unless we see some data from the manufacturer for a particular bulb, I don't know that we have a good handle on the voltage, current, or frequency. Edit: It could even be very good if the manufacturer would supply the buyer with the details of the physics that are going on in his particular...

The above is a photo of a 4'0" snowman that I made today, New Year's Eve 2025, in Chicago. We had about a half inch of snow, but packing was ideal with temperatures slightly above freezing.

Just an additional comment or two: What you @Orthoceras are asking seems simple in a way, but plasma physics can get very complicated, and the best we might be able to do is get a reasonably accurate idea of what is going on inside the lamp. Years ago, as an undergraduate student, I did an...

one micron=1.24 eV so that 620 nm=orange is 2.48 eV. The energies you have there are all in the UV if I'm not mistaken. I don't know the answer though to why the streamer is blue and the pads are orange. The orange would be of lower energy than the blue. The ionization potential for argon...

The OP may find it of interest that as the degree of ionization in a plasma increases, basically as the current density rises, the electrical resistance decreases. That way, once a path, i.e. an arc, through the plasma is established, it tends to stay there with some stability. This is what...