13 th September 2012 – 0v6 Radiation Tolerant Power Converter Controls thanks to: TE/EPC/CC, Y. Thurel, A. Masi, M. Brugger, G. Spiezia et al…

CERN TWEPP 2012 CERN CERN Accelerator Complex Lake Geneva Geneva Airport CERN LAB 1 (Switzerland) CERN LAB 2 (France) Proton Synchrotron (PS) Super Proton Synchrotron (SPS) Large Hadron Collider (LHC) 27km long 150m underground

CERN TWEPP 2012 CERN, the LHC and Machine Protection CERN 3 of 23 CERN Accelerator Complex Large Hadron Collider (LHC) Beam-1 Transfer Line (TI2) Beam-2 Transfer Line (TI8) Beam Dumping Systems Super Proton Synchrotron (SPS) 100us for one turn,

CERN TWEPP 2012 CERN CERN Accelerator Complex CMS ALICE ATLAS LHC-b

CERN TWEPP 2012 CERN CERN Accelerator Complex CMS ALICE ATLAS LHC-b

CERN TWEPP 2012 CERN CERN Accelerator Complex CMS ALICE ATLAS LHC-b

CERN TWEPP 2012 Introduction Power Converters = Power Supplies Critical for operation of CERN’s machines Direct impact on beam quality Direct impact on machine availability x x x x x x LS 1-2 ≈6.5≈3 x ≈1 x Year Peak Energy [TeV] Peak Intensity [p] Peak Luminosity [cm -2 s -1 ] 7 [1,2,3]

CERN TWEPP 2012 Introduction Power Converters = Power Supplies Critical for operation of CERN’s machines Direct impact on beam quality Direct impact on machine availability x x x x x x LS 1-2 ≈6.5≈3 x ≈1 x Year Peak Energy [TeV] Peak Intensity [p] Peak Luminosity [cm -2 s -1 ] 8 LS1 = Long Shutdown #1 – from 2013 to 2014 – upgrade magnet interconnects LS2 = Long Shutdown #2 … [1,2,3]

CERN TWEPP 2012 Introduction Power Converters = Power Supplies Critical for operation of CERN’s machines Direct impact on beam quality Direct impact on machine availability x x x x x x LS 1-2 ≈6.5≈3 x ≈1 x Year Peak Energy [TeV] Peak Intensity [p] Peak Luminosity [cm -2 s -1 ] 9 Function Generator Controller F Increasing energy and intensity = increasing levels of radiation in machine environment existing converter controls would have low availability when higher energies and intensities are reached in the LS 1-2 era GC Function Generator Controller FGClite a design optimised for high availability in radiation = the next 25 years of LHC [1,2,3]

CERN TWEPP 2012 Power Converters & Controls

CERN TWEPP 2012 Magnet Powering Circuit 11

CERN TWEPP 2012 Magnet Powering Circuit 12

CERN TWEPP 2012 Magnet Powering Circuit 13

CERN TWEPP 2012 Power Converter 14

CERN TWEPP 2012 Power Converter Closed Loop Current Regulation Converter State Control (ON/OFF/RESET) Machine Protection Interlocks Diagnostics 15

CERN TWEPP 2012 Power Converter Types 16 [4,5]

CERN TWEPP 2012 Power Converter Types Function Generator Controller F G C 17 [4,5]

CERN TWEPP 2012 Radiation Effects

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) prompt cumulative 19

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) defects accumulate and gradually destroy the silicon lattice 20

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) SIO 2 21

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) SIO 2 22

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) accumulate and gradually degrade the transistor function SIO 2 23

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) electrons collected by junctions creating parasitic current SE Transient (SET) SE Upset (SEU) SE Functional Interrupt (SEFI) SIO 2 24

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) CMOS parasitic bi-polar transistors… Switch on = short drain to source… SE Latch-up (SEL) 25 N P N P N P

CERN TWEPP 2012 in a nutshell 1. Displacement Damage (DD) 2. Total Ionising Dose (TID) 3. Single Event Effects (SEE) cumulative prompt SE Latchup (SEL) SE Transient (SET) SE Upset (SEU) SE Functional Interrrupt (SEFI) Non-Ionising Energy LossGrays lifetime! random in time failure! Cross-section mitigation is possible… 26

CERN TWEPP 2012 Surface Buildings Power converters are installed in one of five areas with machine radiation risks: none Perpendicular galleriesnone - low Parallel gallerieslow Alcovesmedium - high LHC Tunnel high [6]

CERN TWEPP 2012 Power converters are installed in one of five areas with machine radiation risks: Power Converter

CERN TWEPP 2012 Power Converter Types 29 [4,5] ≈1000 FGClite needed… FCG2

CERN TWEPP 2012 FGClite

CERN TWEPP 2012 FGC2 31

CERN TWEPP 2012 Function 32

CERN TWEPP 2012 Software versus Programmable Logic 33 µPDSP

CERN TWEPP 2012 Interesting Points use several FPGAs, figure the rest out later… Is this becoming a standard design practice? power converter electrical interface = same Programmable Logic needs special attention in mission critical systems Voltage Source, Interlocks, DCCT will all be the same interface power converter operational functions = same The LHC is still going to be the LHC after LS1… FGC2 PCAD 2002 Xilinx Schematic Entry Altium Designer VHDL FGClite FGC2 hardware documentation limited… 10 years… technical motivations in the mind of previous experts FGClite hardware requirements document = reverse engineering FGC2 before starting… Ouch! 34

CERN TWEPP 2012 Design Flow

CERN TWEPP 2012 Design Flow for Radiation Tolerance 36

CERN TWEPP 2012 Design Flow for Radiation Tolerance Class 0 (C 0 ) Class 1 (C 1 ) Class 2 (C 2 ) components known to be resistant, or easily replaced, conceptual design not influenced by these components. components potentially susceptible to radiation, in less-critical parts of the system. Substitution of parts or mitigation of issues is possible with a re-design. components potentially susceptible to radiation, in more-critical parts of the system. The conceptual design is compromised if these components do not perform well. Substitution of parts or mitigation of issues would be difficult. Resistors, capacitors, diodes, transistors… Regulators, memory, level translators… ADC, FPGA, fieldbus driver 37

CERN TWEPP 2012 Design Flow for Radiation Tolerance 38

CERN TWEPP 2012 Design Flow for Radiation Tolerance 39

CERN TWEPP 2012 Design Flow for Radiation Tolerance 40

CERN TWEPP 2012 Design Flow for Radiation Tolerance 41 [7]

CERN TWEPP 2012 Lifetime & Reliability

CERN TWEPP 2012

CERN TWEPP 2012

CERN TWEPP 2012 Stress screening Run in Burn in Maintenance Plan considered by Reliability Analysis Programmable Logic?

CERN TWEPP 2012 FGClite Reliability Requirements acceptable failure rate < 40 per year… Mean Time Between Failures > hours (1000 units x 8800 hours per year) / 40 electrical SEE radiation cross-section cross-section <1 x > hours 46 [7]

CERN TWEPP 2012 FGClite Reliability Requirements acceptable failure rate < 40 per year… Mean Time Between Failures > hours electrical SEE radiation cross-section <1 x > hours equipment lifetime > 25 years… electrical DD / TID radiation >200 Grays design for 25 years 47

CERN TWEPP 2012 In Closing…

CERN TWEPP 2012

CERN TWEPP 2012

CERN TWEPP 2012 Visions of the Future “Fly like you test, test like you fly” risk is never zero mitigate the risks in every other way first more simple function = better move equipment… shield equipment …is the equipment’s function really needed? it does the minimum needed… it does it very well... risks assessed for additional features… Trust… but verify specify function... formalise if needed… test against function… follow the V-model… make tests as realistic as possible = test-bench function, test environment As Low As Reasonable Possible (ALARP) follow a strict development plan basic design has to be rock solid before adding complications for radiation to design a system for use in radiation… 51 [8]

CERN TWEPP 2012 Visions of the Future “Fly like you test, test like you fly” risk is never zero mitigate the risks in every other way first more simple function = better move equipment… shield equipment …is the equipment’s function really needed? it does the minimum needed… it does it very well... risks assessed for additional features… Trust… but verify specify function... formalise if needed… test against function… follow the V-model… make tests as realistic as possible = test-bench function, test environment As Low As Reasonable Possible (ALARP) follow a strict development plan basic design has to be rock solid before adding complications for radiation to design a system for use in radiation… in machine protection 52 [8]

CERN TWEPP 2012 fin – thank you!

CERN TWEPP 2012 References From the Chamonix Performance Workshop [1] 54 Extracted from [2] Extrapolated from W. Herr’s talk: “Luminosity Performance Reach After LS1” [3] Derived from [4] Photographs courtesy Y. Thurel et al, from: “LHC Power Converters the Proposed Approach” [5] Diagram background is from [6] Figures and flow derived from work by Y. Thurel and S. Uznanski[7] Several sources – not an original statement from CERN. E.G. [8]