Saturday, November 22, 2008

200-inch Aluminizing - more photos

Here is a batch of photos from last week's aluminizing of the 200-inch mirror. BIG THANKS to Susan V for capturing these shots while I was away at Corning. She did a super job!

Remember to click on the images for more aluminizing goodness.

The Palomar day crew working under and inside the 200-inch mirror cell prior to the mirror's removal from the telescope.

The 200-inch mirror removed from the telescope, sitting on the aluminizing cart.

That's one dirty mirror.

Tools of the trade for washing telescope mirrors.

Washing the 200-inch mirror.

"You missed a spot."

"Green River" is applied to the surface of the mirror to strip away the thin coating of aluminum. This reveals the mirror's honeycombed backside. Notice that some aluminum still remained on the right side of the disc when this was taken.

The final aluminum is stripped from the mirror.

The mirror is covered overnight to protect the clean surface.

The 17.5-ton bell jar is lifted as the mirror gets a final air cleaning to remove any dust from the surface of the glass.

One of the three glow discharge events prior to aluminizing the mirror.

Two of the 220 coils fire to deposit the thin layer of aluminum to the surface of the mirror.

If you haven't yet, be sure to check the post below for the "official" before and after shots of the mirror.


santosh said...

Thanks Susan, for those fantastic pictures!
Feel really lucky to be able to witness such interesting events sitting on the opposite side of the globe.
BTW, what is "Green River"

Anonymous said...

what's the chemical name of 'green river'?

Scott Kardel said...

Green River is a mix of a dilute solution of hydrochloric acid & copper sulfate.