R. Messner May 2004 Readiness Review LST Gas System R. Messner May 2004 Readiness Review

Will cover a few of the items below Gas Mix – the issue of what gas mixtures will be allowed in the LST system has been resolved FHA: O’Neill, Budnick HEEC review Gas Mixing System In leak test Want to test output flows ASAP Integrate with the GIB Gas Interrupt Box (GIB) Finished with checkout Had found problems with firmware; fixed IR-2 Distribution Panels Flow restrictor in hand, checked out Gas Supply Manifolds Next to be assembled Gas Shack Safety System Expansion underway Electrical External Monitor System

Gas Mix Instead of getting a specific mix approved, we want approval for a region of mixes

Gas Mix The operating region takes into account the stability we have seen in the RPC system

Mixing System Functionality A fourth mass flow meter can provide a tie-breaking vote in case of MFM/MFC disagreement Can also pick up small drifts in mixed gas flows Shut-off solenoids will close if the gas mix drifts out of the allowed region

Gas Rack - in leak test

Gas Rack

Gas Interrupt Box Functionality

GIB in checkout

Overview of the IR-2 Distribution

Silica tubing flow resistor

Check of silica tubing flow resistance

Gas Shack Layout Two new inert gas supplies; Each will have a shutoff valve, orifice, overpressure releases Construct a new isobutane supply rack and manifold; Will have two isobutane shutoff valves, orifice

Summary The loose ends involved in determining a permissible gas mix have been resolved Very close to having a functional mixing system with its monitor system to ensure a non-flammable and a runnable mix Use air or nitrogen, check the self consistency and stability of system It is important to keep moving ahead; sufficient and timely technical support is critical Want the gas rack in the gas shack before the end of May Delayed a bit because we want to get the manifolds done first; then we can do more things in parallel Expansion of Gas Shack safety system in progress EPICs monitor system will be the next item to attack

Spare Slides

Looked at the recent performance of the RPC system Snapshots taken a week apart, a half day at a time This is a measure of the stability of the gas mixture +- 0.0005 out of 0.045 Or ~ 1.0 % of the reading

Recent performance of the RPC system Isobutane Fraction in Gas Mixture