NEH 1.2 or Tender X-ray Instrument (TXI)

There are three primary goals for the Tender X-ray Imaging (TXI) instrument:

  1. A beamline designed to incorporate X-ray Pump and X-ray Probe techniques especially in the emerging field of nonlinear X-ray science.
  2. A general purpose coherent scattering/forward diffraction instrument for sub-micron samples covering the "tender" X-ray range. Which is loosely defined to be between the Si K edge of 1.8 keV, and the Fe K edge of 7.1 keV.
  3. And a system to conduct tender X-ray spectroscopy measurements.

Endstation Description

The operational challenge for the NEH 1.2 instrument development is the minimization of overhead associated with changing experiment types while maintaining flexibility to explore new and developing methods and science. These challenges will be met with a fixed end stations and sample chamber. The primary sample chamber will have a well defined, standardized kinematic mounting system for mechanical equipment inside the large sample vacuum chamber. Additionally standardized motor, power/signal and liquid/gas sample feedthroughs will be provided and documented for use by all user groups. This will allow for the interchangeability of user provided mechanical systems to improve flexibility and allow for assembly and maintenance outside of the hutch.

An ePix10k-HR detector will be used as the primary forward scattering detector. The detector is designed for highest efficiency in the 2 to 5 keV photon energy, It will have >2 MPixels with each pixel being able to be single photon as well as provide a dynamic range of 10,000 photons per pixel. The forward scattering detector will collect scattering up to 3 Angstroms resolution. Additionally a downstream detector will be provided that is located >1 m away from the interaction point. This will provide a flexible detector geometry for nonlinear interactions.

Specifications

Parameter Required Goal Comment
Photon Energy Range SXU [eV]
Photon Energy Range HXU [eV]
1250-5000
1750-7000
250-5000
1000-7000
Need to reject harmonics outside of required range
ΔE / E SXU
ΔE / E HXU
SASE
SASE
1 x 10-3
1 x 10-4
Desired Seeded on SXU and delay line will double as monochromator on HXU
Beamline Transmission [%] 50 90/70 B4C / Ni respectively
Max FEL Power [W] 200    
Experimental Spot Size Range
  1. Horizontal [μm]
  2. Vertical [μm]
1-10
1-10
<1-10
<1-10
Finite bendable KB mirrors for both SXU and HXU beams
Beam Position Stability
[% of FWHM]
<10   Required for overlap of SXU and HXU beams

Advisory Panel

  • Uwe Bergmann - SLAC
  • Adrian Mancuso - European XFEL
  • Claudio Masciovecchio - Elettra
  • Chris Milne - PSI
  • Robert Duarte - LBL
  • Garth Williams - BNL
  • Janos Hajdu - Uppsala Universitet
  • David Reis - SLAC
  • Ian Robinson - UCL