1. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno QXF Test Requirements Ruben Carcagno BNL Workshop December 17, 2013

2. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno US Deliverables – Q1 and Q3 Cold Masses Both identical Each requires two 4.8m long cold masses (MQXF) Total of 20 individual (10 paired) cold masses to be delivered by the US QXF Magnet Types – SQXF: “Short” prototypes – LQXF: “Long” prototypes – MQXF: Production QXF Magnets 2

3. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno MQXF Deliverable Options 1.Cold Mass (coils and Al. Shell), ~4.3 m long, no test 2.He SSL vessel 4.3 m long single tested magnets to be paired, aligned, welded and tested as a cryostated assembly at CERN. 3.Fully finished SS He Vessel double magnet, ~9 m long, with inter- magnet connection(s) Scope #3 Scope #2 Scope #1 U.S. CERN

4. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Geometry and Parameters 4

5. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Preliminary Test Objectives At room temperature: – Hipot Measurement – Magnetic Measurements Rotating probe measurements Measurements during cooldown and warmup – RTD measurements – Strain Gauge measurements – Residual Resistivity Ratio (RRR) Measurements Measurements at 4.5 K and 1.9 K: – Hipot Measurement (at 4.5K only) – Magnetic Measurements Rotating probe measurements – Quench Training up to 90% of short sample limit – Quench Characterization Voltage taps measurements Quench Antenna measurements – Quench Propagation Studies – Ramp Rate Dependence Measurements – Voltage Spikes Measurements – Energy Loss Measurements (at 4.5K only) – Splice Measurements (at 4.5K only) A thermal cycle will be included. – 1.9 K testing after the thermal cycle should be enough to assess training memory. And we will do some magnetic measurements to check the field quality reproducibility after the thermal cycle. At room temperature: – Hipot Measurement – Magnetic Measurements Rotating probe measurements Measurements during cooldown and warmup – RTD measurements – Residual Resistivity Ratio (RRR) Measurements Measurements at 1.9 K: – Hipot Measurement – Magnetic Measurements Rotating probe measurements – Quench Training up to 90% of short sample limit – Quench Characterization Voltage taps measurements Quench Antenna measurements No Thermal Cycle SQXF and LQXFMQXF

6. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno MQXF Configurations The exact configuration for MQXF cold mass testing has not been decided yet, and it depends on the final agreement between the US and CERN for the MQXF deliverable. The following options are possible examples: – Testing a single MQXF cold mass with or without the stainless steel shell on a vertical test stand – Testing a single MQXF cold mass with a stainless steel shell on a horizontal test stand – Testing a double MQXF cold mass with a Stainless Steel shell on a horizontal test stand. In this case, the test stand should be capable of powering each cold mass independently and together. For options (2) and (3), a reusable cryostat where the cold mass is inserted and then removed would be needed for testing.

7. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Requirements Cooldown/warmup – Maximum gradient between magnet ends < 100K Test Temperature: 1.9K – Stability: +/- 20 mK Temperature Measurements – Up to 5 CERNOX sensors, Range: room temperature to 1.9K Absolute accuracy at 1.9K: +/- 10 mK Hipot – Coil to ground, heaters to ground, and heaters to coil: 1,000 V with < 2 uA leakage current at room temperature in air and cold in LHe (preliminary, hipot voltage may need to be higher)

8. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Requirements (Cont.) Maximum Test Current: 21.5 kA – Short Sample Limit at 1.9K Number of Quenches – Plan for at least 30 quenches at 1.9K. In production 4.5K training can be avoided unless we find a specific issue in the magnet requiring temperature dependence to understand it. Maximum Current Ramp Rate: 400 A/s – User-adjustable and changeable during ramp Magnetic Measurements – Room Temperature Rotating Probe (100 mm diameter) on 150 mm cold mass aperture – Include Field Strength and Harmonics

9. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Quench Protection Quench Detection Channels and Thresholds – (WC – Ref) Threshold: 5 V – (WC – Idot) Threshold: 3 V – (HC – HC) Threshold: 100 – 2,500 mV Thresholds must be current-dependent to overcome voltage spikes at lower currents – Trigger delay: < 1 ms minimum Heaters – 16-20 Strip Heaters wired in 4-5 user-configurable independent groups User-adjustable delay in the range 0 – 1000 ms – Up to 4 spot heaters Energy Extraction Resistor – Configurable between 2.5 mΩ to 50 mΩ User-adjustable delay in the range 0 – 1000 ms

10. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Quench Characterization Up to 80 Voltage Taps for QC Up to 40 Quench Antenna Channels Flexible user configuration DAQ – Minimum sampling rate: 10 kHz – Minimum # pre-trigger samples: 20,000 – Minimum # post-trigger samples: 20,000 – Minimum time window: 4 seconds

11. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Voltage Spikes Dedicated half-coil segment voltage taps provided for voltage spike measurements DAQ – Continuously sampling at > 100 kHz – Threshold in the range 5 mV to 1,000 mV – Data logging after crossing threshold with a 0.5 second minimum – Synchronization with magnetic measurement system

12. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Strain Gauges Up to 64 4-wire resistive strain gauge bridge configurations Readings performed at a maximum interval of 1 minute during cooldown We plan strain gauge measurements at high frequency (close to 1 Hz) during every current ramp up. This is to check for pole unloading at high current and for repeatability

13. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Misc Energy Loss Measurements – Performed at 4.5K using a current range of 500 – 6500 A and a ramp rate in the range 20-300 A/s RRR Measurements – Performed form 4.5K to 300K recording current and voltages Splice Measurements – Coil splice measurements at 4.5K one at a time using special voltage taps at each side of the splice and measuring voltages with a high precision DMM while stepping current up to the maximum of short sample current

14. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Schedule SQXF Test Facility – Operational by November 2014 – Total of 4 LARP full SQXF cold masses LQXF Test Facility – Operational by August 2015 – Total of 4 LARP full LQXF tests – Last test November 2017 MQXF Test Facility – Operational by November 2018 – Total of 20 LARP MQXF tests Either as 20 independent single cold masses or 10 double cold masses (to be determined) – Last test May 2021

15. HL-LHC/LARP, QXF Test Facility Workshop– R. Carcagno Test Cycle Duration Test cycle: installation, cooldown, test, warmup, and removal Assumptions (to be validated) – SQXF: 2 months – LQXF: 2 months – MQXF (single cold mass): 1 month – MQXF (double cold mass): 2 months For the first two production cold masses, a learning factor multiplier of 1.5 and 1.25 is assumed for the test cycle duration