Saturday, September 27, 2008

Through the Looking Glass

It looks like we had a successful test of the aluminizing system for the 200-inch mirror on Friday. The chamber wont be opened for a while yet though.

Here are some (hopefully) interesting shots for you. The chamber has a porthole-like window on the side and it is possible for the crew to peak in on the action. I was fortunate enough to be able to grab some photos during the action.

The first shows the first of three glow discharges. A small amount of gas is introduced into the chamber and turned into a plasma (ionized gas). The photo was an exposure of over 1 second and doesn't capture the flickering nature of the plasma. It is a beautiful sight.

The second photo looks into the chamber as aluminum is being deposited. Over 200 tungsten wire coils with aluminum melted on to them lie within. Electricity is applied to the coils in pairs. As this happens they are heated in excess of 1,000 degrees and the aluminum is vaporized. Because all of the air has been pumped out of the chamber, creating a vacuum, the aluminum atoms fly about unimpeded. As each hits a surface they stick and gradually lay down a thin layer of aluminum.

In the photo below you can see two of the tungsten coils glowing brightly and another (in the upper right) that has just finished its job but glowing with residual heat.

Below is a movie of the view looking inside the vacuum chamber. I don't think that anyone other than observatory staff has had the opportunity to see something like this before. The photos used to make the movie were all with a hand-held camera and were all taken with the same exposure speed. This allows you to see the coils heat up and fade away as is described in the photo above.

Enjoy!

video

2 comments:

Edward said...

WOW. That is Awesome. Thanks for once again taking us behind the scenes. It is really interesting to see the inner workings of Palomar.

Is there a reason that they are waiting to open the chamber?

Scott Kardel said...

The wait was because we have fewer staff members on hand during the weekend and other projects were pressing on Monday & Tuesday.

An update will be posted soon.