David Nisbet – LIUWG 17 th July 2008 LIUWG – Options for Powering Phase I David Nisbet Summary of points from LIUWG 7 Existing topology Future topology ideas Overview of possible topologies Summary of options Discussion…

David Nisbet – LIUWG 17 th July 2008 Existing Triplet Q3Q2bQ2aQ1 i1 i2 i3 ifwd3 Inductive coupling Complex

David Nisbet – LIUWG 17 th July a 3 2b MQXC I Q2 = = kA I Q3 = 12.3 kA I Q1 = 12.3 kA 13kA V cv1 - Cost - Easy to control - Volume but - No flexibility (IQ1=IQ2a=IQ2b=IQ3) - Quench protection - String test LIUWG7 – Proposal1

David Nisbet – LIUWG 17 th July kA V cv2b 1 2a 3 2b MQXC I Q2 = = kA I Q3 = 12.3 kA I Q1 = 12.3 kA 13kA V cv1 13kA V cv3 13kA V cv2a - Full flexibility (easy to control ) - Easy for quench protection (no heater, no extraction) - no string test but -Cost ( f[voltage] => distance from DFB) - volume LIUWG7 – Proposal2

David Nisbet – LIUWG 17 th July a 3 2b 13kA V cv1 V cv2 MQXC I F = = kA I Q3 = 12.3 kA I Q1 = 12.3 kA - Easy to control - Two identical strings but -IQ1 = IQ3 and IQ2a = IQ2b (Possible to add trims on Q1 or Q3? How many % ?) LIUWG7 – Proposal3

David Nisbet – LIUWG 17 th July 2008 Phase I Triplet – LIUWG7 Proposals Several options for powering Optimum choice is a compromise of – Ease of protection – Electrical complexity – Volume – Cost LIUWG7 – Baseline retained was for a single 13kA source with 3x 600A correctors The following slides expand on all the possible options

David Nisbet – LIUWG 17 th July 2008 Magnet and Cryostat Layout? Cold Link to UJ Separate Link for D1? Lead configuration indicative only

David Nisbet – LIUWG 17 th July 2008 Option1 – Individual Powering

David Nisbet – LIUWG 17 th July 2008 Option1 – Individual Powering No bypass diodes No EE Switch / resistor No 4Q trim PCs No coupling Simple… Current Decay Time (I=0A) – R= 300uOhm, L = 52mH, t = ~14 min – Note: ramp down of RB/RQF/RQD = 30min… Control of negative ramp rate – 1Q converters – Particularly limited at low current Volume – Existing Triplet: 10 Racks, 18.6kA installed – Phase 1: 24 Racks, 56kA installed Current Leads: 5x 12kA continuous

David Nisbet – LIUWG 17 th July 2008 Option2 – Main Feed with 1Q Trims

David Nisbet – LIUWG 17 th July 2008 Option2 – Main Feed with 1Q Trims 1x bypass diode No EE Switch / resistor No 4Q trim PCs Volume – Existing Triplet: 10 Racks, 18.6kA installed – Phase 1: 8 Racks, 18kA installed Current Leads: 5x – 2x 12kA continuous – 3x 12kA peak; 2kA continuous Current Decay Time (I=0A) – R= 300uOhm, L = 208mH, t = ~57 min – Note: ramp down of RB/RQF/RQD = 30min… Control of negative ramp rate – 1Q converters – Particularly limited at low current Inductive coupling of 4 systems

David Nisbet – LIUWG 17 th July 2008 Option3 – Main Feed with 1Q Trims and EE

David Nisbet – LIUWG 17 th July 2008 Option3 – Main Feed with 1Q Trims and EE No 4Q trim PCs Volume – Existing Triplet: 10 Racks, 18.6kA installed – Phase 1: 8 Racks, 18kA installed Current Decay Time 4x bypass diode – Leakage current? Precision? Proximity to current leads? Current Leads: 5x – 2x 12kA continuous – 3x 12kA peak; 2kA continuous Control of negative ramp rate – 1Q converters – Particularly limited at low current Inductive coupling of 4 systems

David Nisbet – LIUWG 17 th July 2008 Option4 – Main Feed with 4Q Trims and EE

David Nisbet – LIUWG 17 th July 2008 Option4 – Main Feed with 4Q Trims and EE Volume – Existing Triplet: 10 Racks, 18.6kA installed – Phase 1: 7.5 Racks, 15.8kA installed Current Decay Time Control of negative ramp rate – 4Q converters (but only for trim) 4Q trim PCs – Active bypass protection 4x bypass diode – Leakage current? Precision? Proximity to current leads? Current Leads: 5x – 2x 12kA continuous – 3x 12kA peak; 600A continuous Protection more complex – requires detailed study Inductive coupling of 4 systems

David Nisbet – LIUWG 17 th July 2008 Option5 – Split Powering1

David Nisbet – LIUWG 17 th July 2008 Option5 – Split Powering1 1Q trim PCs Volume – Existing Triplet: 10 Racks, 18.6kA installed – Phase 1 : 14 Racks, 18kA installed – Potential for N+1 trims and 22kA installed in same volume 4x bypass diode – Leakage current? Precision? Proximity to current leads? Protection straightforward Inductive coupling of 2 systems Current Leads: 6x – 4x 12kA continuous – 2x 12kA peak; 2kA continuous Control of negative ramp rate – 1Q converters – Particularly limited at low current Current Decay Time – R= 300uOhm, L = 108mH, t = ~30min – Note: ramp down of RB/RQF/RQD = 30min…

David Nisbet – LIUWG 17 th July 2008 Option6 – Split Powering2

David Nisbet – LIUWG 17 th July 2008 Option6 – Split Powering2 Current Decay Time 1Q trim PCs Volume – Existing Triplet: 10 Racks, 18.6kA installed – Phase 1 : 14 Racks, 18kA installed – Potential for N+1 trims and 22kA installed in same volume 4x bypass diode – Leakage current? Precision? Proximity to current leads? Protection straightforward Inductive coupling of 2 systems Current Leads: 6x – 4x 12kA continuous – 2x 12kA peak; 2kA continuous Layout of DFB for protection and leads Control of negative ramp rate – 1Q converters – Particularly limited at low current Current Decay Time – R= 300uOhm, L = 108mH, t = ~30min – Note: ramp down of RB/RQF/RQD = 30min… Internal connection from Q1 to Q3

David Nisbet – LIUWG 17 th July 2008 Option7 – Split Powering1 with EE

David Nisbet – LIUWG 17 th July 2008 Option7 – Split Powering1 with EE Current Decay Time 1Q trim PCs Volume – Existing Triplet: 10 Racks, 18.6kA installed – Phase 1 : 14 Racks, 18kA installed – Potential for N+1 trims and 22kA installed in same volume 4x bypass diode – Leakage current? Precision? Proximity to current leads? Protection straightforward Coupling – Inductive coupling of 2 systems – Resistive coupling of 2 systems through switch resistance Current Leads: 6x – 4x 12kA continuous – 2x 12kA peak; 2kA continuous Two 12kA EE systems required – but at half energy of single system Control of negative ramp rate – 1Q converters – Particularly limited at low current

David Nisbet – LIUWG 17 th July 2008 D1 and Corrector Powering Volume – Existing Correctors: 6 Racks, 5.04kA installed – Phase 1 Correctors + D1 : 8 Racks, 12.64kA installed Existing LHC designs can be used – Existing correctors: 8x [±600A, ±10V] – Phase 1 Correctors: 4x [±600A, ±10V] – Hopefully re-use existing 4Q 600A correctors

David Nisbet – LIUWG 17 th July 2008 Summary Table OptionDescription 1 PO*** Individual Powering – 4x 12kA 1Q Individual PCs – 24 Racks, 5x 12kA current leads 2Main feed with 1Q Trims – {1 x 10kA, 3 x 2kA} PCs – 8 Racks, {2x 12kA + 3x 12kA peak} current leads – Inductive coupling 3Main feed with 1Q Trims and EE – {1 x 10kA, 3 x 2kA} PCs, 1x 12kA 208mH EE, Warm bypass diodes – 8 Racks, {2x 12kA + 3x 12kA peak} current leads – Inductive coupling 4Main feed with 4Q Trims and EE – {1 x 12kA, 3 x ±600A} PCs, 1x 12kA 208mH EE, Warm bypass thyristors – 7.5 Racks, {2x 12kA + 3x 12kA peak} current leads – Inductive coupling, complex protection

David Nisbet – LIUWG 17 th July 2008 Summary Table (contd) OptionDescription 5 PO** Split Powering1 – {2 x 12kA, 2 x 2kA} PCs, Warm bypass diodes – 14 Racks, [4x 12kA + 2x 12kA peak} current leads – Inductive coupling 6Split Powering2 – {2 x 12kA, 2 x 2kA} PCs, Warm bypass diodes – 14 Racks, [4x 12kA + 2x 12kA peak} current leads – Inductive coupling, internal wiring from Q1 to Q3 7Split Powering1 with EE – {2 x 12kA, 2 x 2kA} PCs, 1 x 12kA 104mH EE, Warm bypass diodes – 14 Racks, [4x 12kA + 2x 12kA peak} current leads – Inductive and resistive coupling

David Nisbet – LIUWG 17 th July 2008 Conclusion Powering Preferences Individual Powering is preferred choice (Option 1) – Can powering be made from the surface (long cold link)? – Perhaps volume and cost constraints – No issues with radiation and access; installation in advance… Second choice is for Split Powering1 Is an Energy Extraction system really necessary, or can we rely on Heaters?