What's it mean when ...

An argon is really reluctant to start, even after a full current burn in for a few hours?

I know my little argon works, however it is really annoying getting to start still.

Anyone know what I could do to try get it starting first click?

When its trying to start, you'll get a few really bright promising flashes, and sometimes it'll eventually stay lit, but sometimes it wont want to stay lit at all. However, you have to ramp up the current a bit, and eventually it must heat up or something far enough and it stops producing the bright flashes.

Cheers,
Dan

Just doing a bit more reading, a dominant green line means high tube pressure, and a dominant 488nm line and lack of green line means low tube pressure. My green line is very comparable to the 488nm line, so the problem is still high tube pressure by the looks of it

Things,
I'm still relatively new to lasers as a whole, while I did have a Toshiba HeNe that I scavenged from a 17" video disk player,, about twenty years ago. I find your thread very interresting. While I don't claim to know what you are talking about with the lines, the flickering sounds like failure of the gas to ionize and continue conducting. If so, wouldn't that be a voltage problem and not current?? If I'm off base and boring, please forgive and just ignore me, but maybe the thinking will help. Hope so, good luck.

Yes, it is a result of the voltage being too low ideally, however the voltage is only too low when the gas pressure in the tube is high.

When the lasers sit for a while, the gas buried in the outside of the tube leaks back in, raising the gas pressure. The higher pressure takes a higher voltage to keep ionized, which is why it's finding it hard to start. Once you've got it running, you run it at full power for 2 days or so, which re-buries the gas into the tube walls.

I am trying to start it again so I can do the gas burying process, with minimal luck.

Thanks for the response. Very informative. Sorry mine wasn't of any help. Good luck gettin' 'er back up and hummin'.

Things said:

the voltage is only too low when the gas pressure in the tube is high...

The higher pressure takes a higher voltage

Click to expand...

To explain the lines, argon can be made to lase at several wavelengths, even at the same time with appropriate optics. A multiline argon produces several distinct colors mixed in a single beam which can be separated by a prism or dichroic mirrors. The gain on each line varies and depends on gas pressure and other factors which causes the intensity of each wavelength produced to vary relative to the other colors.

HeNe gas will lase on several different lines as well ranging from green to IR, but the gain is much too low to get a stable output on more than one at a time so HeNe optics are specifically designed to amplify only a specific line, 632.8nm red being the most common by far.

As for the hard starting, it can be either high gas pressure, a tube that is just tired in general, or a weak igniter.

Got it lit again