EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS Electromagnetic vs. Permanent Magnet Quadrupoles Heinz-Dieter Nuhn, SLAC / LCLS June 28, 2004 Pros for designs NLC Prototype (30 being produced for Orion) LCLS Design Pros for designs NLC Prototype (30 being produced for Orion) LCLS Design

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS Permanent Magnet vs. Electromagnetic Quadrupoles Pros of Permanent Magnet Quadrupoles Reduced cost (No plumbing, no power supplies and cabling) Reduced space requirements Sufficient for baseline design Not subject to power supply failures or instabilities. (Low gradients would amplify trajectory error amplitudes) Pros of Electromagnetic Quadrupoles Allows to measure beam kicks due to quadruple offsets after Beam Based Alignment Procedure to as additional measure to verify BBA as means to track field errors. Allow for inclusion of dipole trim windings for fine control of quad center Pros of Permanent Magnet Quadrupoles Reduced cost (No plumbing, no power supplies and cabling) Reduced space requirements Sufficient for baseline design Not subject to power supply failures or instabilities. (Low gradients would amplify trajectory error amplitudes) Pros of Electromagnetic Quadrupoles Allows to measure beam kicks due to quadruple offsets after Beam Based Alignment Procedure to as additional measure to verify BBA as means to track field errors. Allow for inclusion of dipole trim windings for fine control of quad center

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS NCL Quadrupole (Isometric Draft)

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS NLC Quadrupole (Isometric View)

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS NCL Quadrupole (Front View)

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS SLAC Electrical Discharge Machine (EDM) Used like jig saw but producing smooth surfaces.

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS NLC Quadrupole (Measurement Bench Arrangement)

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS NLC Prototype Quadrupole

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS NLC Prototype Quadrupole (Side View)

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS NLC Prototype Quadruple (Rear View)

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS SLAC EM Quad Design (Carl Rago) The NLC Electric Quad was designed a number of years ago attempting to demonstrate that a 20% change in field, during beam based alignment, would produce a magnetic center shift of less than 1 micron. This has been repeatedly demonstrated by this prototype near maximum field. At lower operating fields the center shift increases with a 20% change but remains under 2 microns. This quad is in competition with Fermilab’s development of an adjustable permanent magnet which I believe has yet to reach the design goal but is making significant progress. [Might be too weak for the LCLS] This prototype was also designed to address manufacturing and reliability improvements suggested to the standard SLAC quad design. The changes included: EDM profiling of a monolithic core assembly High current ‘quick disconnect’ electrical terminals Round copper conductor with ‘quick wound’ racetrack coils I believe that this design concept can be successfully adjusted to the needs of the Undulator. The design and prototype was produced for about 11K$. In a quantity of 30 this should be a very cost effective component. The NLC Electric Quad was designed a number of years ago attempting to demonstrate that a 20% change in field, during beam based alignment, would produce a magnetic center shift of less than 1 micron. This has been repeatedly demonstrated by this prototype near maximum field. At lower operating fields the center shift increases with a 20% change but remains under 2 microns. This quad is in competition with Fermilab’s development of an adjustable permanent magnet which I believe has yet to reach the design goal but is making significant progress. [Might be too weak for the LCLS] This prototype was also designed to address manufacturing and reliability improvements suggested to the standard SLAC quad design. The changes included: EDM profiling of a monolithic core assembly High current ‘quick disconnect’ electrical terminals Round copper conductor with ‘quick wound’ racetrack coils I believe that this design concept can be successfully adjusted to the needs of the Undulator. The design and prototype was produced for about 11K$. In a quantity of 30 this should be a very cost effective component.

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Electromagnetic Quad Isometric View Including 1 trim winding on each quadrant for additional dipole correction, equivalent to 16 microns displacement. Extend of larger radius windings can be reduced.

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS Electromagnetic Quad Design Specifications ( Carl Rago) rm0.005 kGdL (Max)T kGdL (Min)T Effective Lengthcm B' (Max)T/m Bp (Max)kG Amp-TurnsAT Coil-TurnsTurns Layers ConductorEach0.25 Rd Ideal Current (Max)A Core Efficiency%98.00% Real Current (Max)A MTL ?in Resistance per ft conductorOhms Resistance per MagnetOhms Current DensityA/in Voltage Drop Magnet (Max)V Voltage Drop Cable (Max)V Total VoltageV Power Magnet (Max)W Power Cables (Max)W Total Power (Max)kW

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS ConclusionsConclusions Going from permanent magnet to electromagnetic quads appears feasible. Needs cost estimate and refined design. Needs cost estimate and refined design. Going from permanent magnet to electromagnetic quads appears feasible. Needs cost estimate and refined design. Needs cost estimate and refined design.

EM vs. PM Quads Linac Coherent Light Source Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center Undulator Meeting, June , 2004 Heinz-Dieter Nuhn, SLAC / LCLS End of Presentation