Overview

The Hall A detector gas systems are located in the Hall A Gas Shed alongside of the truck ramp for Hall A. The gas cylinders in use are along the outside of the Gas Shed in a fenced area. There are racks next to the Gas Shed for storage of full gas cylinders. On the other side of the truck ramp there are racks for storage of both full and empty cylinders. Hall A currently uses ethane, argon, ethanol, two grades of CO2 and nitrogen.

One system uses two cylinders of SFC grade CO2 (without a helium head). This is for the gas Cerenkov counters in the HRS detector arrays.

One system uses two cylinders of Coleman grade CO2. This is for flushing the aerogel Cerenkov counters in the HRS detector arrays.

One system uses a single cylinder of Coleman grade CO2. This is for the gas Cerenkov counter in the (e,p) setup in the beamline.

One system uses two cylinders of Zero grade argon and two cylinders of Chemically Pure grade of ethane. This is for all the HRS wire chambers of both arms. The two gases are mixed inside the Gas Shed and bubbled through ethyl alcohol. Details of this system can be found in the Hall A Wire-chamber Gas System (HAWGS) manual. A copy of the current manual is in Counting Room A and on the Hall A web page.

One cylinder of Industrial grade nitrogen is used to provide pressurized gas for a few automatic cylinder switch-overs in the systems.

Maintenance of the gas system is routinely performed by the Hall A technical staff. Shift personnel are not expected to be responsible for maintaining the detector gas systems. Unexpected maintenance requirements should be handled by contacting

 

Jack(John) Segal - pager and phone are both extension 7242

 

Hall A Technician on call