CFHT Information Bulletin, number 39, Second Semester 1998



CFHT Comes Clean

Dan Wilcox, CFHT, wilcox@cfht.hawaii.edu

CFHT has a new facility, a class 100 clean room. This gives CFHT personnel the ability to work on camera dewars, CCDs, and other sensitive items in a clean, static-free, environmentally controlled area.

The clean room has been set up in room 71, Dan Sabin's old office. A static conductive floor was installed. Then a 12' x 16' (approximately 4 x 5 meters) modular clean room was put up in the back of the room Inside this clean room are a couple of workbenches, a laminar flow bench, and some storage for CCDs, etc. The anteroom (the rest of the former office) has storage, a workbench and vacuum pump.

This clean room has highly filtered air blown into it to keep a positive pressure inside, which keeps dirt out of the clean room. A class 100 clean room means that there are 100 or fewer particles per cubic foot of air (approximately 3400 particles m-3). In an ordinary office, there are about 30,000 particles per ft3 (100,000 m-3). In an office where someone smokes, there is about 500,000 particles ft-3 (1.5 million m-3). All of this dirt is potentially harmful to a sensitive CCD. In an attempt to prevent ruining an expensive device by working on it in a dirty environment, CFHT install this clean room.

In order to keep the particle count as low as possible, anyone entering the anteroom is to put on booties over their shoes and step on sticky floor mats just outside and inside the door. When entering the clean room, they put on a "bunny suit", face mask, safety glasses, a cap, and gloves. This attire will keep most of the particles on everyday clothing from coming off and polluting the clean room. We have done some tests with a particle counter on clothing and that produced a dramatic illustration of just how dirty humans are! So, please, observe the signs posted on the door into the anteroom and on the door into the clean room.

Wearing all of this protective clothing makes a person hot and sweaty. This is not good for sensitive devices, so we are eagerly awaiting the installation of the air conditioner. When that is installed, we will have a clean room that will be a used extensively for working on all the new CCDs yet to arrive, as well as the CCDs and dewars already in hand.

I want to thank all the people that put in a tremendous effort in getting this room prepared (this is kind of like the Oscars, if I have forgotten anyone, I apologize). Bob Anderson, for organizing all the bits and pieces, Roger Wood for his invaluable help all along, Tom Beck, for all his electrical work, Grant Matsushige, for all his help putting this together, Dan McKenna for his help in getting all the stuff organized in there, Bobby Song, for his help laying the floor, etc, Barney Magrath for sharing his knowledge and his help in obtaining supplies, Moani Akana for her help in straightening out the phones, Katrina Wilcox for helping set up and clean it, and Rohendra Atapattu for his help in obtaining an air conditioner for the room.

We now have a very good place to work with our sensitive equipment. With a little cooperation and help, we can keep this facility clean and useable with a minimum of maintenance.





Editor: Dr. Timothy M. C. Abbott, tmca@cfht.hawaii.edu
Copyright © 1998, CFHT Corporation. All rights reserved.