1. LARP MQXF Magnets Cryogenic Testing at Fermilab’s Industrial Building 1 Roger Rabehl Technical Division/Test & Instrumentation Department January 31, 2014

2. Cryogenic Testing of MQXF Magnets at Fermilab Operational phase durations for cryogenic testing of MQXF magnets at Fermilab have been estimated for both single and double cold mass cryostats. These phases are: – Cool-down from 300 K to 4.5 K – Pump-down from 4.5 K to 1.9 K – Recovery/refill at 4.5 K following a quench – Warm-up from 4.5 K to 300 K

3. Updated Operational Figures of Merit – Horizontal Testing Assumptions: Cool-down and warm-up – Each MQXF cold mass is treated as a 9570 kg, low- carbon steel lumped capacitance. – 10 g/s He supply flow rate with 75 K  T (FRS: 100 K  T max.). – He supply temperature range of 4.5 – 300 K. – Cool-down:  T = Max. magnet temp. – He supply temp. – Warm-up:  T = He supply temp. – Min. magnet temp.

4. Updated Operational Figures of Merit – Horizontal Testing Calculated results: cool-down and warm-up – 1 MQXF Cool-down to 4.5 K: 68 hr Warm-up to 300 K: 93 hr – 2 MQXF Cool-down to 4.5 K: 137 hr Warm-up to 300 K: 186 hr

5. Updated Operational Figures of Merit – Horizontal Testing Assumptions: 1.9 K pump-down time – Scales with LHe volume (feedbox below lambda plate + magnet) using Q2a&b operational data Feedbox below lambda plate: 400 liters Q2a&b (cold masses + external HX): 400 liters MQXF: 250 liters/cold mass Feedbox + Q2a&b: 800 liters Feedbox + 1 MQXF: 650 liters Feedbox + 2 MQXF: 900 liters

6. Updated Operational Figures of Merit – Horizontal Testing Calculated results: 1.9 K pump-down * Historically, the first 1.9 K of each day is longer than subsequent pump-downs that day. This is because the test stand is put into overnight condition (i.e., shut off the LHe supply and let the test stand ride on compressor suction) each night with the penalty of refilling and a longer initial pump-down as the test stand re-stabilizes the next day. This strategy needs to be revisited. 1.9 K pump-down [hr] Q2a&b3 1 MQXF2.5 2 MQXF3.5

7. Updated Operational Figures of Merit – Horizontal Testing Assumptions: 4.5 K recovery/refill following quench – Scales with stored energy using Q2a&b operational data Q2a or Q2b: 1.4 MJ Q2a&b: 2.8 MJ 1 MQXF: 5.3 MJ 2 MQXF: 10.6 MJ

8. Updated Operational Figures of Merit – Horizontal Testing Calculated results: 4.5 K recovery/refill Stored energy [MJ] 4.5 K recovery/refill [hr] Q2a or Q2b1.40.5 Q2a&b2.81 1 MQXF5.32 2 MQXF10.64

9. Present Cryogenic Capabilities LQX quadrupole testing figures of merit – ~30 hour cool-down from 300 K to 4.5 K – 6 hour pump-down from 4.5 K to 1.9 K – 3 hour quench recovery

10. Updated Operational Figures of Merit – Horizontal Testing Calculated results: 1.9 K pump-down * Historically, the test stand is put into overnight condition (i.e., shut off the LHe supply and let the test stand ride on compressor suction) each night with the penalty of refilling and a longer initial pump-down as the test stand re-stabilizes the next day. This strategy needs to be revisited. Initial 1.9 K pump- down per day [hr] Subsequent 1.9 K pump-down [hr] Q2a&b63 1 MQXF52.5 2 MQXF73.5