1. E906 Gas System 1/7/09 LANL Meeting D. Northacker UIUC

2. E 906 Gas System 2 mixtures required: argon/ethane (50/50, through isopropyl alcohol), CF4/isobutane (50/50). Inert gas required: nitrogen, possibly argon/CO2 (80/20) as safe test gas. Sources: cylinders for all gases, probably dewars of argon, possibly ethane trailer if justified.

3. E906 Gas System ST 1 needs CF4/isobutane. ST 2,3 need argon/ethane. ST 4 may need CF4/isobutane. ST 1 requires about 2 ft3/hr (1 L/m). ST 2,3,4 require about 4 ft3/hr each. Total argon/ethane: 8 ft3/hr (4 L/m). Total CF4/isobutane: 6 ft3/hr (3 L/m).

4. E906 Gas System Cost of argon/ethane is $0.12 per ft3, or $4 per 1000 L. Cost of CF4/isobutane will range from $2- $4 per ft3, or about $100 per 1000 L. For 8 ft3/hr argon/ethane, we have $800/month. For 6 ft3/hr CF4/isobutane, we have $6k/month.

5. E906 Gas System Equipment Required: 2 mixers, 4 distribution racks, high pressure regulators/manifolds, possibly CF4/isobutane recirculation system. Equipment Available: nearly intact CF4/isobutane mixer (HyperCP), 2 partial argon/ethane mixers (FOCUS), 1 distribution rack (SELEX), probably enough surplus regulators/manifolds for shed (leftover from Ktev and others). Additional distribution equipment also available (photohelics, solenoid valves, flow meters, etc.). Surplus recirculation/analysis equipment from ANL also available.

6. E906 Gas System Layout (upstairs): Cylinders, high pressure regulators/manifolds, both mixers, alcohol bubbler are all in shed (located at south face of building). Ethane trailer and argon dewars would be just outside the shed. There will be a flowmeter panel indicating flow rates to each of the 4 stations, located inside the shed. Shed will be accessible 24/7.

7. E906 Gas System Layout (downstairs): All distribution racks will be located on the experimental floor. Gas selection valves (inert/working), flowmeters, chamber pressure gauges, solenoid valves, will be monitored by cameras and/or other remote sensors. These racks will be inaccessible with the beam on, but should be stable once equilibrium conditions are achieved.

8. E 906 Gas System Schedule: 2 months shed work, 4 months mixers, 6 months distribution/hall piping, 4 months documentation/safety interactions, 4 months (estimate) for CF4/isobutane recirculation system. Main work will start in May. Some work involving parts and documentation searches already started.

9. E906 Gas System Overall view - argon/ethane: Mixing and distribution well understood. Existing designs for racks built during mid-90s will be re- implemented. An ethane trailer can be added if desired. Overall view – CF4/isobutane: Successfully mixed for HyperCP, but without recirculation. Non-trivial issues (both safety and technical) associated with recirculating fluorocarbon/ hydrocarbon mixtures are not well understood. Some R&D will likely be required before design can be finalized.

10. E906 Gas System Cost to finish shed: $3k-$5k. Cost to finish mixers: $8k-$10k. Cost to finish distribution racks: $10k-$12k Cost for hall piping: $5k-$7k. Cost for recirculation: maybe $20k, assuming availability of surplus ANL components. Total is about $30k (without recirc), assuming that at least half of what we need is available as surplus from FNAL.

11. E906 Gas System Concerns: Amount of time to get job done – barely enough if all goes well. Chamber leak rates – need to be less than 0.25 ft3/hr (110 cc/m) for any detector using a flammable mixture (FNAL rule). If recirculation is implemented, leak rate should be less than 10 cc/m per detector (at the operating pressure). Discuss recirculation issues with both industrial and research experts. Possible long-term contract for CF4 price break.