NSLS-II Photon Sources & Beamline Systems Qun Shen Director, Experimental Facilities Division (XFD) NSLS-II Beamline Development Information Meeting April 14, 2010 Email: qshen@bnl.gov

Outline NSLS-II Photon Sources Beamline Systems Baseline & planned photon sources Spectral brightness & flux Optimization of insertion devices Beamline Systems Overview of beamline systems Beamline optics and expected performance characteristics Guideline to design and construction schedule Technical assistance by light sources staff

Design Parameters of NSLS-II Storage Ring NSLS-II Design Parameters Ring energy (GeV) 3 Ring current (mA) 500 Ring circumference (m) 792 Number of DBA cells 30 Number of 9.3 m straights 15 Number of 6.6 m straights bh in 9.3 m straights (m) 20.1 bv in 9.3 m straights (m) 3.4 bh in 6.6 m straights (m) 1.8 bv in 6.6 m straights (m) 1.1 Vertical emittance (nm-rad) 0.008 Horizontal emittance (nm-rad) 0.55 RMS energy spread (%) 0.1 RMS pulse length (ps) 15-30 Time between bunches (ns) 2 Revolution period (ms) 2.64 Number of bunches 1056 Average bunch current (mA) 0.47 Average bunch charge (nC) 1.25 Overview of one super period of NSLS-II storage ring

Typical Sector Layout at NSLS-II Low-b ID 3PW / BM High-b ID

Electron Source Size sh,v and Divergence s’h,v Type of source Low-b Straight Section (6.6m) High-b Straight Section (9.3m) 0.4T Bend Magnet 1.14T 3-Pole Wiggler σh (μm) 33.3 107 125 167 σh' (μrad) 16.5 5.1 91 98 σv (μm) 2.9 5.2 13.4 12.3 σv' (μrad) 2.7 1.5 0.80 0.82 High-b Straight Section (9.3m) 3-pole Wiggler Bending Magnet Low-b Straight Section (6.6m)

Six Beamlines in NSLS-II Construction Project Inelastic X-ray Scattering (IXS) Hard X-ray Nanoprobe (HXN) Coherent Hard X-ray Scattering (CHX) Coherent Soft X-ray Scattering & Polarization (CSX) Sub-micron Resolution X-ray Spectroscopy (SRX) X-ray Powder Diffraction (XPD) CSX 23-ID XPD 28-ID SRX 21-ID CHX 5-ID HXN 3-ID Note: beamline location assignments preliminary Conceptual design report posted at http://www.bnl.gov/nsls2/docs/PDF/ CDRs_SixProjectBeamlines_NSLS-II.pdf IXS 10-ID

Currently Planned Insertion Devices at NSLS-II Type of Device Purpose Quantity Damping Wiggler (DW90): 90 mm period, 1.85 T, 2× 3.5 m Broadband 3 In-Vacuum Undulators (IVU): IVU20: 20-mm period, 1.05 T (> 5 mm gap), 3 m IVU21: 21-mm period, 0.91 T (> 5.5 mm gap), 1.5 m, canted IVU22: 22-mm period, 0.76 T (> 7 mm gap), 2× 3 m (tentative) Hard X-ray 2 1 Elliptically-polarizing undulator (EPU49): 49-mm period, 0.94 T (> 11.5 mm gap), 2× 2 m long, optionally canted by ~0.16 mrad Soft X-ray Three-Pole Wiggler: 1.14 T peak field, 20-cm long Undulators can be canted by 0-2 mrad in both low-b and high-b straight sections DWs can also be canted but requires modification of vacuum chamber Canting angle 0-2 mrad

Current and Potential Insertion Devices at NSLS-II EPU49 DW90 SCW60 BM 3PW Type IVU CPMU SCU EPU PMW SCW Bend Photon energy range [keV] 1.9–20 1.8-20 2.1-25 1.8-40 0.18–7 <0.01– 100 <0.01– 200 <0.01 – 12 <0.01 – 25 Type of straight section Low-β High-β Period length, lU [mm] 20 22 17 14 49 90 60 Total device length [m] 3.0 6.0 ~3 ~2 4.0 7.0 1.0 0.25 Number of periods 148 270 ~174 ~140 2 x 39 75 0.5 Minimum magnetic gap [mm] 5 7 11.5 12.5 15 28 Peak field linear mode B [T] 1.03 0.74 ~1.1 ~1.7 0.94 1.85 3.5 0.40 1.14 Max Ky in linear mode 1.83 1.52 ~2.2 4.34 15.7 19.6 Peak field circular mode B [T] 0.57 Max K=2 Ky in circular mode 3.69 Min. hn fundamental [keV] 1.6 1.8 ~2.1 ~1.8 0.17 Critical energy [keV] 11.1 21 2.39 6.8 Maximum total power [kW] 7.9 9.1 ~9.2 ~16 8.8 67 34 0.32 Horizontal angular power density [kW/mrad] 16 6.6 0.023 0.067 On-axis power density [kW/mr2] 66 ~80 ~105 32.8 62 25 0.088 0.26 * Requires additional R&D, with CPMU17 as near-term and SCU14 as far-term options

Spectral Brightness of NSLS-II Sources at 500mA

Spectral Flux of NSLS-II Sources at 500mA

Spectral Flux of NSLS-II Sources (cont’d)

Wiggler Comparisons

Spectral Flux of NSLS-II Infra-Red Sources Standard gap BMs provide excellent mid and near IR sources; Large gap (90 mm) BMs provide excellent far-IR sources

Optimization of Undulator Performance Given Accelerator Constraints Radia Model (central part) IVU Parameters O. Chubar (NSLS-II) Reference Geometry: Pole Width: 40 mm Pole Height: 25 mm Pole Thickness: 3 mm (for λu = 20 mm) Materials: Pole: Va Permendur NEOMAX Magnet: NdFeB Magnet Width: 50 mm Magnet Height: 29 mm IVU Lengths Satisfying Vertical “Stay Clear” Constraints in Low- and High-Beta Straight Sections Fundamental Photon Energy vs Gap for Different IVU Periods (E = 3 GeV) βy0 = 3.4 m βy0 = 1.06 m λu= 20 mm λu= 21 mm λu= 22 mm λu= 23 mm

Maximal Spectral Flux through 100 μrad (H) x 50 μrad (V) Aperture Spectral Flux of Different IVUs – IXS “Candidates” – Satisfying e-Beam Vertical “Stay Clear” Constraint Maximal Spectral Flux through 100 μrad (H) x 50 μrad (V) Aperture E-Beam Energy: 3 GeV Current: 0.5 A NSLS-II High-Beta (Long) Straight Section ~9.13 keV Such insertion device optimization is done during conceptual design Not necessary for beamline development proposal O. Chubar (NSLS-II) ~9.13 keV

Three-pole Wigglers Added to provide hard x-ray dipole radiation with no significant impact on the emittance Up to 30 can be added to the lattice upstream of each dipole B -1.5 mrad 0 mrad 3PW BM-B BM-A +2.125 mrad +2.5 mrad +4.25 mrad

3PW and BM Power Density Distributions Magnetic Field Power Density Distribution from different parts of TPW and BM at 30 m (single-electron emission, integral over all photon energies, horizontal cuts at y = 0) |θX| = 4.25 mrad |θX| ≈ 2.6 mrad θX= 0 1.65 mrad O. Chubar (NSLS-II)

3PW and BM Intensity Distributions (Hard X-rays) Intensity distributions at different photon energies at 30 m from 3PW show effects from soft poles in 3PW and from adjacent BMs Effect of such non-ideal intensity distribution on microfocusing is being studied by a working group, and updates will be provided O. Chubar (NSLS-II) Vertical Cuts at x = 0 Horizontal Cuts at y = 0

Beamline Systems Overview Utilities and safety system (PSS, EPS) Front-end (inside storage ring tunnel) Endstation and experiment controls Enclosures and beam transport Photon optical system

Optical Systems Beamline optical systems are key functional elements of any synchrotron beamline. Functions may include: Monochromators (single-crystal optics, gratings, multilayers) Beam conditioning (mirrors, focusing optics) Beam filtering (spectral filter, harmonic rejection mirror, spatial filter or beam-defining slits) Power handling (high heat-load optics) Imaging optics (zone-plate objective) HXN Beamline Optical Layout (top view) Yong Chu (NSLS-II)

Power Outputs from Insertion Devices O. Chubar (NSLS-II) APS U33 2.4m produces similar power per unit solid-angle as NSLS-II IVU22 6m

Cryogenic vs. Water Cooling of Si Optics NSLS-II U20 @ min. gap: 1.8mm(h) x 0.9mm(v) Bragg angle = 14o Absorbed Power ~113W Peak Temp: 116.5 K Slope Error: 0.4 mrad (due to thermal bump) Cryogenically cooled Si is needed (and is expected to work) for NSLS-II undulator sources Water cooling is adequate for NSLS-II 3PW/BM sources V. Ravindranath (NSLS-II)

Variety of Cutting-Edge Focusing X-ray Optics Kirkpatrick-Baez (K-B) mirrors Large acceptance aperture, achromatic focusing for easy energy scanning Focal size limited by critical angle: achieved ~25 nm Compound Refractive Lens Refraction effect is weak so requires many lenses Shape errors affect focal size: achieved ~50 nm Conventional Fresnel zone plate (FZP) Easy to use, good efficiency for soft x-rays but poor efficiency for hard x-rays Focal size limited by smallest features that can be fabricated: achieved ~15 nm Multilayer Laue-Lens (MLL) High aspect ratio (>1000) Fresnel zones can be fabricated; good for hard x-rays Difficult to tune energy Theory shows <1 nm possible: achieved ~16 nm (1D) Multilayer mirrors Good energy tunability; requires ultralow surface finish and precision ML deposition Focal size limited by ML mirror slope errors: achieved ~8 nm (1D) Above – XRF imaging of a test pattern, scanned through 2D focusing by crossed MLL, with resolution ~20nm x 40nm Yan, Conley, Lima et al. (NSLS-II) Maser, Macrander, Shu et al. (ANL)

Canted Beamline Example: SRX Beamline KB branch ZP branch Thieme et al. (NSLS-II) Two x-ray branches using two ~1.5m long U21-type undulators canted by 2 mrad Two hor. mirrors to deflect ZP beam out to allow ~0.5 m separation in ZP hutch

Coherent Soft X-ray Beamline Full polarization control branch Sanchez-Hanke, Reininger, et al. (NSLS-II) Coherent branch Two soft x-ray branches using 2x EPUs canted by 0.16 mrad Branching mirror M1-A to deflect beam outward for the coherent branch

NSLS-II Project Beamline Schedule

Assisting Users in Beamline Proposal Process BNL Light Sources scientific staff are part of the scientific user community, and their expertise can be very useful in the beamline development proposal process. NSLS-II and NSLS staff are encouraged to help out user groups who may need certain guidance and technical assistance This help may be in following forms Providing advice and guidance in specific area of expertise; Providing specific technical information such as source properties and existing optical concepts of existing project beamlines; and Helping to address certain technical issues on conceptual level if appropriate. Due to limited resources, NSLS-II and NSLS would not be able to provide engineering assistance on technical problems during BL proposal process

Beamline Development Sources & Optics Group Beamline Development Sources & Optics Group has been established to assist user groups on specific technical information and on addressing specific technical issues that may have broad interest in the community Users are encouraged to contact the members in specific areas of expertise Members of the Group: Steve Hulbert (hulbert@bnl.gov) – Leader Oleg Chubar (chubar@bnl.gov) – source properties Ruben Reininger (rreininger@bnl.gov) – gratings and mirrors Lonny Berman (berman@bnl.gov) – crystal optics and heat load Zhong Zhong (zhong@bnl.gov) – high energy x-ray monochromators Andy Broadbent (broadbent@bnl.gov) – utilities and safety systems Group meets weekly to discuss any issues that requires attention; XFD Director participates in these meetings to provide oversight and to communicate any additional information as needed

Beamline Development - Beamline Contact Group Beamline Contact Group consists of existing beamline group leaders and others with specific expertise in particular type of beamlines; User groups are encouraged to contact the appropriate staff for questions and answers generally related to the type of beamlines of interest. Beamline Contacts: Cecilia Sanchez-Hanke / Ruben Reininger – soft x-ray and VUV beamlines Lonny Berman – 3-pole wiggler and bend-magnet x-ray beamlines Eric Dooryhee – Damping wiggler x-ray beamlines Andrei Fluerasu / Juergen Thieme – undulator x-ray beamlines Beamline contact may seek additional help from the Sources and Optics group to discuss any technical issues, by communicating the topic to any member in the Sources and Optics group.

Thank You! Questions ??