Monday, February 26, 2007

Laser-Induced FluoresceANTS!

So today has been a steaming pile.

I had to move my equipment into another room in the chemistry building as there was no way to make a dark room in labs where people were working. Fortunately there is a huge room at the end of one hallway I could use. Now, its been freaking hot in Thailand lately. Oh, and humid. Its like Alabama summertime right now. Like a cross between Tatooine and Degobah. No A/C in the building, though it did have small windows I could open...

Except I had to cover all those up with aluminum foil to shut out all the light to focus the system. You see, sunlight will burn out a silicon photodiode (detector) faster than you can say "sunlight will burn out a silicon photodiode (detector)." So all windows had to be sealed and covered in the name of SCIENCE.

So I'm standing (sweating) in the dark, over my laser system, trying to focus the beam onto a tiny crystal cell, when I start getting little shocks on my hands and arms. At first I thought they were electrical shocks at any rate, even though the first thing I did last week was ground the table to the outlet (my only available ground). So I shut down the system and turned on the lights.

Do you see them? That's right. Red ants. Now, I'm not going to announce that they were fire ants, but they certainly liked to bite. However I don't have any raised bumps so I don't think they are fire ants. Nevertheless they enjoyed feasting on me in the dark.

They were all over the system.

Can you see the little guys in that second picture? There is about 8 of them near the mount.

First of all, I couldn't understand why the heck ants would be interested in laser optics. But more importantly I had to figure out how the heck they were getting up onto the table. Then it hit me.

The same reason I couldn't possibly be getting shocked is the mechanism by which the ants can assault my system (and me). They are coming out of the outlet and climbing up my makeshift grounding wire.

So today I had to disconnect the ground and all the power cables, move the system to another table, take apart all the optics and clean out all the ants. I can't imagine what kind of signal I'd get if one of those buggers walked across a lense while I was firing the laser. Though I may have to see how they resond to 5mW of 635nm electromagnetic death now that I think about it. In any case, the building is infested with ants, and its likely they climbed up to hang out on the cool metal optical table I set up. Being made of aluminum it has a fairly low thermal conductivity.

So now I've got to figure out how to keep the ants off my system, but still ground the table to the outlet (no, draping the ground through a bucket of water isn't safe), and then set the whole goddamn thing back up.

Science in the jungle.