MeV-UED Specifications
Scientific Capabilities
Scientific Application | Technique |
---|---|
Time-resolved measurement of electron–phonon coupling | Measurement of Debye-Waller effect on multiple lattice reflections |
Time-resolved studies of momentum resolved phonon dynamics | Thermal diffuse scattering measurement |
Measurement of melting dynamics | Single-shot pump–probe measurements |
Three dimensional measurement of structural dynamics | Measurements of positional change of multiple lattice reflections at different sample orientations |
Measurement of chemical photodissociation or photoisomerization | Gas-jet UED |
Measurement of novel phase of quantum materials | Cryo-UED |
Source Parameters
Parameter | Value |
---|---|
Electron beam energy | 2 - 4 MeV |
Repetition rate | Single shot → 360 Hz* |
Charge per pulse | 1 - 100 fC (104 - 106 electrons) |
Beam emittance | 2 - 20 nm-rad |
Bunch length | <150 fs FWHM** |
Momentum resolution | <0.17Å-1 |
Beam spot size | 100-200 um (typical), 10 um (FWHM) focused |
*Upgrade planned in 2022
**Beam charge dependent
Optical Laser Properties
Parameter | Value |
---|---|
Repetition rate | Single shot → 360 Hz |
Wavelength range | 200 nm, 266 nm, 400 nm, 800nm, 240 nm - 2 µm tunable, 3-15 µm tunable |
Typical optical pulse energy | > 8 mJ @ 800 nm |
Nominal pulse duration | 75 fs (FWHM) |
Optical delay | 0 - 3 ns (physical delay stage) |
Optical spot size | 200 - 1500 µm (FWHM) |
Detectors
P43 phosphor screen & Andor iXon Ultra 888 EMCCD | |
---|---|
Phosphor thickness | 50-100 um |
Point-spread-function | 85 um (rms) |
Pixel size | 13 x 13 um2 |
Sensor size | 1024 x 1024 |
Data format | .tiff |
Pixel well depth | 80k e- |
ePIX detector - direct electron detection* | |
---|---|
Pixel size | 100 x 100 um2 |
Frame rate | 360 Hz |
Sensitive area | 5 x 5 cm2 |
Gain mode | 3 fixed plus 2 with auto ranging and programmable switch point |
S/N in High Gain per MeV electron | >100 |
*Offered under a commissioning/best-effort basis. Contact UED staff for details.
MEC CONTACT INFO
Eric Galtier
Scientist (Instrument Lead)
(650) 926-6227
egaltier@slac.stanford.edu
Ariel Arnott
Area Manager (Instrument)
(650) 926-2604
amarnott@slac.stanford.edu
Jonathan Ehni
SEA (Instrument)
(650) 926-4562
jonehni@slac.stanford.edu
Dimitri Khaghani
Scientist (Instrument)
(650) 926-5009
khaghani@slac.stanford.edu
Hae Ja Lee
Scientist (Instrument)
(650) 926-2049
haelee@slac.stanford.edu
Bob Nagler
Scientist (Instrument)
(650) 926-3810
bnagler@slac.stanford.edu
Philip Heimann
Scientist (Instrument, X-ray Beam Delivery)
(650) 926-8772
paheim@slac.stanford.edu
Eric Cunningham
Scientist (Lasers)
(650) 926-2548
efcunn@slac.stanford.edu
Marc Welch
Engineer (Lasers)
(650) 926-3754
mwelch@slac.stanford.edu
Control Room: (650) 926-7970
MEC Hutch: (650) 926-7974
Vestibule: (650) 926-7976