MEC Specifications

MEC Beamline Components cartoon — MEC Schematic

Source Parameters

Photon Energy	2.5-25 keV for 1^st harmonic*
Photon Energy	Up to 25 keV for 2^nd and 3^rd harmonic*
Source Size	60 x 60 µm² (HxV) FWHM @ 8.3 keV
Source Divergence	2 x 2 µrad² (HxV) FWHM @ 8.3 keV
Repetition Rate	120 Hz
Pulse Duration	60 - 300 fs (high charge mode)
Pulse Duration	<10 fs (low charge mode)
Pulse Energy	0.3-2.2 mJ (for nominal 30 fs pulse; photon energy dependent)
Beamline Transmission	Depends on photon energy, 10% (4 keV) - 40% (8 keV)
Photons per Pulse	~1 x 10¹² (high charge mode @ 8.3 keV)
Photons per Pulse	~1 x 10¹¹ (low charge mode @ 8.3 keV)
Focusing Capability	Lens stacks appropriate to given photon energy. Tuned from a couple of microns to several tens of microns by moving target out of focus.
Unfocused Beam Size (8 keV)	Up to 1,000 x 1,000 µm² FWHM @ 8.3 keV
Energy Resolution ΔE/E	~0.2% (bandwidth of LCLS beam)
Energy Resolution ΔE/E	1.4 x 10^-4 (with a Si(111) monochromater)

See machine parameters for more information on the source.

* Energies below 4 keV are in principle usable but the beam size at the end station is large leading to reduced flux. Fundamental goes to 25 keV, where both fundamental and harmonics are cut off by the HOMS transport mirrors common to all hard X-ray instruments.

Long Pulse Laser System

Technology	Frequency Doubled Nd:Glass system
Wavelength	527 nm
Pulse Length	5 - 35 ns ("best effort" for pulse duration down to 2 ns)
Pulse Energy on Target	4 arms polarization multiplexed into two beams with energy depending on pulse length and shape: each arm up to ~25 J at 527 nm in a 10 ns square pulse, with a maximum peak power of all arms combined of 10 GW. Contact MEC staff for details.
Repetition Rate	~1 shot per 7 minutes (or ~3.5 minutes for one beam interleaved; pulse shaping quality may be reduced)
Focusing Capability	Flat top spatial profile: 150, 300, and 600 µm diameter spot size with Continuous Phase Plates Direct focus: 250 mm focal length aspheric lenses. Note that the wavefront is of poor quality for focusing without phase plate.

Short Pulse Laser System

Technology	Ti:Sapphire CPA laser system
Wavelength	800 nm (400 nm also available)
Pulse Length	40 fs
Pulse Energy on Target at 800 nm	1 J (at 5 Hz), 5 mJ (at 120 Hz)
Repetition Rate	5 Hz
ASE Contrast	>10⁸
Focusing Capability	f/5 OAP in standard delivery, <10 µm FWHM focus; I > 4x10¹⁹ W/cm²

See more laser details

Diagnostics

MEC-specialized Pixel Array Detectors	ePix10k Quad (384 x 352 modules; 4 per Quad) Sensor thickness: 1 mm Si (double of standard) 100 x 100 µm² pixel size Max signal (8 keV photons) 11000; r.m.s. noise: 320 eV DAQ rate: up to 120 Hz EMP-resistant enclosure and cabling
X-ray Thomson Scattering Spectrometers	Energy ranges: 4-8 and 7.5-25 keV Crystals: HAPG (von Hamos) Resolving power (@ 8 keV): 1.13x10^-3 Scattering angles: fixed horizontal (by configuration) DAQ rate: up to 120 Hz
X-ray Transmission Crystal Spectrometer	Energy range at high resolution of about 1.5 keV at central photon energy in range: 6-21 keV Energy range of low resolution mode: 20-200 keV Crystals: Quartz (101) plan for low resolution and assymetric cut (203) for high resolution Resolving power (@ 8 keV): 3 x 10^-4 Fully shielded with 12 mm of tungsten DAQ rate: up to 120 Hz
Line imaging VISAR	Dual camera to remove phase ambiguity Temporal window: 1 ns - 1 ms Temporal resolution: 20 ps Field of view: 0.265 mm at the streak cameras Imaging resolution: 10 µm 0.1 Hz
Alignment diagnostics	Questar long distance microscopes Spatial resolution: 20 µm Field of view: 0.5-5 mm adjustable Motorized focus
XUV spectrometer	Wavelength range: 7 - 35 nm Resolution: 0.08 nm Collection efficiency: 2.5 10^-5 photons detected per emitted photon in 4π DAQ rate: up to 0.2 Hz (with 1 MHz controller) Detector: PI-MTE 2048B