Overview
Beamline 15-2 is a state-of-the-art undulator experimental station specializing in advanced hard x-ray spectroscopy. The end station features cutting-edge instrumentation, including a 7-crystal Johann spectrometer and an 8-crystal von Hamos instrument for sub-core hole lifetime resolution x-ray emission spectroscopy. It also houses high-throughput and high-energy-resolution x-ray Raman spectrometers with resolutions of 0.3 eV, optimized for both low-q (40-crystal) and high-q (30-crystal) scattering geometries. For time-resolved studies, the beamline integrates a high-power MHz repetition rate fiber laser with fast diodes and FPGA electronics, enabling laser-pump x-ray-probe spectroscopy with ~75 ps time resolution, utilizing SPEAR’s camshaft bunch (~20 mA). The versatile end-station supports a wide range of advanced sample environments, including electrochemical cells, thermal catalysis reactors, cryostats, continuous-flow liquid jets, and microfluidic mixers. These capabilities enable a robust and diverse scientific program spanning catalysis, energy science, biochemistry, environmental science, and actinides research.
Source: Undulator (87periods with 22mm/period), low emittance (6.2nrad) lattice.
Status —
Beamline Parameters —
| Energy Range | Resolution ΔE/E | Spot Size | Flux | Angular Acceptance | |
|---|---|---|---|---|---|
| Focused | 4800-18200 | 1.0-15 10-5 | 5x35um2 (or 100x700um2) | ~3x1013 ph/s (Si111) ~ 4x1012 ph/s (Si311) |
N/A |
| Unfocused | 18000-24000 | 10-4 | 500x2000um2 | ~ 4x1011 ph/s (Si311) | N/A |
Optics —
| Monochromator: | Mirrors |
|---|---|
| LN2-cooled Si(111), ϕ = 0o. double-crystal, fixed-exit geometry LN2-cooled Si(311) , ϕ = 0o. double-crystal, fixed-exit geometry | No mirror before mono. A KB mirror system after the mono: KB-M1 mirror (V): Rh-coated Si mirror; 500mm long. KB-M2 mirror (H): Si and Rh coated stripes; 800mm long. |
Source —
Instrumentation —
| Detectors | Multiple single element Vortex solid-state; PIPS diodes, APD diodes, ionization chambers, Pilatus, and Eiger-X. |
|---|---|
| Ancillary | Integrated fast shutter system and variable Al filters to alleviate radiation damage. High power and high rep rate laser: Amplitude Tangerine 50W, Colby time-delay unit, Teledyne Wavemaster 816ZI-B oscilloscope (16 GHz, 80 GS/s), Teledyne ADQ-14bit 4-channel digitizer card (1GSPS/channel), Biologic potentiostat, Asahi Xe light source. |
| Spectrometer | 7-crystal XES spectrometer (http://dx.doi.org/10.1063/1.4803669) |
| 40-crystal XRS (http://dx.doi.org/10.1063/1.4704458) | |
| 8-crystal von-hamos XES spectrometer (https://doi.org/10.1063/1.4737630) |
Sample Environment —
| Standard room temp | Flexible ambient pressure experiments in both air and under controlled He/N2 chamber(s). Liquid cells and replenishing liquid jets. |
|---|---|
| Standard LHe cryostat | Sample temperature ~10 K: single solid sample 4-slot solid sample cassette single solution sample 5-slot solution sample cassette |
| Non-standard setups | Flexibility with various in-situ setups including photo/electro-chemical cells and thermal reactors for operando catalysis. Other customized and/or Users developed sample environments are regularly being integrated. Please, communicate with beam line staff well in advance to ensure your set-up will work. |
Absorption —
| 127um Be |
|---|
