MeV-UED Specifications

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

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

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

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

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 > 0.8 mJ @ 400 nm > 0.08 mJ @ 266 nm ~ 16 µJ @ 200 nm For pulse energies at specific wavelengths (e.g. 260 nm – 750 nm) or other details please contact Patrick Kramer
Nominal pulse duration	75 fs (FWHM)
Optical delay	0 - 3 ns (physical delay stage)
Optical spot size	200 - 1500 µm (FWHM)

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
> 0.8 mJ @ 400 nm
> 0.08 mJ @ 266 nm
~ 16 µJ @ 200 nm
For pulse energies at specific wavelengths (e.g. 260 nm – 750 nm) or other details please contact Patrick Kramer

Nominal pulse duration

75 fs (FWHM)

Optical delay

0 - 3 ns (physical delay stage)

Optical spot size

200 - 1500 µm (FWHM)

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^-

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

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

MeV-UED Contact Info

Mike Minitti

Director, MeV-UED
(650) 926-7427
minitti@slac.stanford.edu

Joel England

UED Accelerator Lead
(650) 926-3706
england@slac.stanford.edu

Alex Reid

UED Instrument Lead
(650) 926-7467
alexhmr@slac.stanford.edu

Xiaozhe Shen

UED Facility R&D Lead
(650) 926-2899
xshen@slac.stanford.edu

Ming-Fu Lin

Associate Staff Scientist
(650) 926-2586
mfucb@slac.stanford.edu

Matthias Hoffmann

Laser Scientist
(650) 926-4446
hoffmann@slac.stanford.edu

Patrick Kramer

Laser Scientist
(650) 926-5148
pkramer@slac.stanford.edu

Xinxin Cheng

Associate Staff Scientist
xcheng@slac.stanford.edu

Fuhao Ji

Research Associate
(650) 926-4678
fuhaoji@slac.stanford.edu

Stephen Weathersby

UED Area Manager
(650) 926-3890
spw@slac.stanford.edu