Initial Design Specifications for the NSLS-II Damping Wiggler XAS Station

Energy range

• 5.7-35 keV, with provisions to reach 90 keV using higher order crystal reflection

Flux

• at least 10¹³ ph/sec to sample over 7-15 keV

Energy resolution

• standard mode (typical Si(111) resolution on high heat load mono)
• high resolution mode (Si(311) or better on resolution refining mono)
• high-res available over 5.7-35 keV energy range

• high-res flux at least 5x10¹¹ ph/sec over 7-15 keV

Spot sizes

• focused bulk: 1x1mm or smaller using toroidal mirror
• unfocused bulk: up to at least 4x40mm using slits
• microbeam: smaller than 5x5 microns using K-B optics

Suitable spectral quality

• continuous spectrum over 1500eV energy scans
• harmonic rejection
• uniform energy and flux distribution across beam footprint
• non-coherent beam

Stability

• position at sample within 5 microns during scan
• scan-to-scan energy repeatability within 0.05eV @10 keV

Scan modes

• step-and-count in all configurations
• continuous (slew) scanning at standard resolution mode

Minimal configurational changes and set-up requirements

• as close to push-button configuration changes as possible

Endstations

1. Bulk:

   • conventional benchtop setup with ample space for sample containment apparatus
   • controlled atmosphere/contained/clean sample environment
   • space for large apparatus

2. Microbeam

   • controlled atmosphere/contained/clean sample environment

Detection

• Core complement of detection technologies, including
• multi-element solid state
• silicon drift
• wavelength-selective (e.g. bent Laue or multi-layer analyzers)
• assorted PIPS, Lytle, ion chambers, etc.,
• area detector for XRD.

Provisions for future upgrades and build-out

• canting of source
• room for second set of beamline optics for independent ops
• robust infrastructure for future needs (detectors, etc.)