RICH filling
This photo shows the RICH and the gas handling system. The filling of this detector is done following an approved procedure.
The first step is to evacuate the radiator volume. We used a high thoughput rotary vane pump that reached a vacuum of a few milliTorr. Next C5F12 is introduced in the vessel by letting it boil out of the spherical container seen in the lower level of the cart. The partial pressure of C5F12 was read with the analoge gauge seen on the side of the detector as well as with the pressure transducer mounted on the other side of the vessel. Once this partial pressure is reached , the valve at the C5F12 container is closed C4F10 is let into the detector.
C4F10 is stored in the white cylinder seen on the floor. A two stage pressure regulator reduces the pressure to 10 psig. The gas flows into the detector till the pressure in this volume reaches the value of 1.25 atm. We let it overpressure by a small fraction because we expected to extract some gas to measure the index of refraction.
On the cart one can see the optic elements of the Young's interferometer as well as the computer used to record the number of interference fringes.
(Created 9-May-2000)