H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Low Emittance Rings Workshop, Oxford, UK July 8, 2013 ALS Brightness Upgrade & Future Plan H. Tarawneh, C. Steier, A. Madur, D. Robin Lawrence Berkeley National Laboratory B. Bailey, A. Biocca, A. Black, K. Berg, D. Colomb, N. Li, S Marks, H. Nishimura, E. Norum, C. Pappas, G. Portmann, S. Prestemon, A. Rawlins, D. Robin, S. Rossi, F. Sannibale, T. Scarvie, R. Schlueter, C. Sun, W. Wan, E. Williams.

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Outline Introduction - ALS Upgrades Brightness Upgrade –Lattice Choice –Magnet Design –Installation/Commissioning Future directions (ALS-II) - Pre-conceptual: Lattice, Magnets, Injection. Summary 2

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Brightness Upgrade Scope: Replacement of the current 46 dipole corrector magnets with 48 combined function magnets (sextupole+HCM+VCM+skew), as well as associated power supplies, controls, interlocks, chamber modifications Project Schedule: - Magnet RFP 6/2010 -Magnet Installation 10/2012-3/2013 -Migration to low emittance 4/2013 Brightness Upgrade 223 microns (FWHM) 68 microns (FWHM) Superbend Sourcepoints 3  ALS for 20 years has been extremely successful in (soft) x-ray science and newer Facilities could provide potentially better performance and better tools

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Why do we add sextupoles? Reducing the equilibrium emittance is achieved changing settings of existing quadrupoles Problem is nonlinear dynamics: –Sextupoles are too weak to correct chromaticity –Strengthening them would dramatically reduce dynamic aperture (lifetime, injection efficiency) Need additional degrees of freedom –‘Harmonic’ Sextupoles –ALS lattice already full – needed to replace existing corrector magnets with multi-magnets Possibility for low alpha operation –THz, short bunches 4

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Lattices for ALS upgrade There are several possible lattices with ~2 nm rad emittance – 3x smaller than the nominal ALS (~6.3 nmrad) Large  x lattice optimizes brightness for the central bends Small  x lattice would optimize brightness for the insertion devices further Current Lattice New Large  x Lattice New Small  x Lattice 5

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Baseline Lattice: Dynamic Aperture Dynamic aperture is fairly large (larger than current lattice) Dynamic Momentum Aperture larger Touschek Lifetime longer than present lattice Despite higher density 6

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Received funding (summer 09) Comprehensive project review (12/09) Awarded magnet contract (9/10) Detailed magnet design review (3/11) Prototypes of 3 magnet types complete (12/11) First set of 13 production magnets shipped (4/12) All magnets received (8/12) Pre-Installed 13 of 48 sextupoles (1/13) Remaining magnets and power supplies installed (3/13) User operation in high brightness mode (2.0 nm emittance) – since (4/13) Project History Existing Correctors Sextupole / Corrector Multimagnets 7

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Top-off calculations with new magnets –Re-analysis necessary, new field profiles –No hardware changes necessary –Wider ranges on topoff interlocks New fs-slicing bump for new lattice –Using MOGA optimization techniques –Making use of new skew quadrupoles –Also evaluating to switch to horizontal slicing –Shorter pulses Supporting analysis of magnet test results – Reducing Commissioning Risk –Hysteresis –Bandwidth –Multipole content Continuing work to explore low b x lattices Accelerator Physics Work 8

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Commissioning Results Measured horizontal photon beam profiles showing the reduction in size and increase in brightness. Above: BL , Below: BL Installation completed on time (Mar/Apr 2013) Quick Commissioning Progress –Benefit of pre-installation and commissioning: orbit feedbacks, detuned upgrade lattice Managed to deliver low emittance beam during BLC shifts – and continue into user operations –3 months ahead of schedule Beamlines able to resolve brightness increase Reliable operation (no faults due to new lattice or hardware so far)

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Beamsize and Beam Dynamics Measurements 10 BL Confirmed larger dynamic and momentum aperture than high emittance lattice Beamsize Reduction

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, Brightness Comparison Comparison to existing and future light sources (and upgrades) Below 1 keV (soft x-ray) ALS is competitive now Future: NSLS-II and Max-4 will outperform ALS above 100 eV Triple Bend Achromat provides very bright bend and Superbend source points from center bend magnets – ALS (2 nm) above NSLS-II 3PW

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013

Looking beyond completed Brightness Upgrade: Assuring world class capabilities for the future Potential upgrade of ALS ring to diffraction limit 100x increase in brightness 100x increase in brightness angle Diffraction Limit upgrade on a 200m circumference ring enables nanoscale microscopes with chemical, magnetic, and electronic resolution Chemical Maps From 20 nm to 2 nm; from 2D to 3D Resolve nano-interfaces in a cathode Observe the flux in a catalytic network Electronic Maps nanoARPES of complex phases at 25 nm resolution Magnetic Maps Thermally-driven domain fluctuations imprinted in speckle at nm resolution new magnets old magnets 13

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Diffraction Limited Light Sources  Recent realization: Still large potential for storage ring sources Smaller vacuum+magnet aperture – Multi bend achromat lattices with low emittance. Actively pursued: MAX-IV, SIRIUS, ESRF-2, Spring8-2, BAPS, …  Transverse diffraction limited to 2 keV for ALS size is possible – ALS-II Using the ALS tunnel to achieve moderate low emittance with moderate cost.

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Ongoing Conceptual Machine Design Work Active Areas of Conceptual Machine Design: Lattice Optimization Injection Collective Effects Engineering Considerations (Magnets-DC/pulsed, RF, Vacuum) Cost/Schedule

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013  Third generation light sources = generous physical apertures (except for IDs which define much smaller admittance) – smaller apertures (factor 3) = much stronger magnets  Nowadays field quality with smaller magnet apertures achievable  MBA lattices provide smaller natural emittances  NEG coating - distributed pumping in small chambers (cheaper) ALS-II Magnet System 0.78 T & 50 T/m Pole Tip Flux: 1.0 T 3000 T/m 2 Pole Tip Flux 0.45T 80 T/m Pole Tip Flux: 0.9 T

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 ALS-II Injection Scheme Brightness evolution  On-axis injection into SR due to small DA Accumulator Ring (AC).  Accumulator ring shares the SR tunnel. AC Lattice Req. (a) DA of ±10 mm. (b) Lifetime ≥2 h. (c) Minimum 4 Straight sections.  Partial Swap-out injection is foreseen Relax requirements on AC ring & pulsed magnets, I=100 mA Storage Ring Accumulator Ring injecting 0.1*I beam Bunch Trains Stored train Stored train Injected train

H. Tarawneh, C. Steier, A. Madur, D. Robin. L.E. Workshop, July 9, 2013 Summary Biggest challenge (as well as opportunity) for ALS – Continuous Renewal –Well balanced plan between machine/facilities upgrades and beamline/endstation renewal Major Machine Renewal example: Brightness upgrade reduced horizontal emittance from 6.3 to 2.0 nm Beamlines can resolve brightness increase and realize (full) benefit Dramatic performance improvements beyond ALS are possible (at moderate cost) and are now being actively studied. 18