XPP Components
A comprehensive overview of the XPP instrument is published in
Journal of Synchrotron Radiation, 22, (2015).
Channel Cut Monochromator
![Channel Cut Monochromator](/sites/default/files/styles/embed/public/2023-10/xpp_monochromator.jpeg?itok=IcDluMI9)
An artificial channel-cut monochromator (CCM) is available for use on the XPP instrument. The system design is adopted from the work of Narayanan et al. (J. Synchrotron Rad. (2008) 15, 12-18). This system currently uses Si (111) crystals and thus has a energy resolution of 1.4 x 10-4 (ΔE/E). The mechanics of this system are appropriate for scanning measurements such as those required for various X-ray spectroscopies. The CCM may be retracted when not needed. Please note that the CCM displaces the beam +7.5 mm in the vertical plane.
X-ray Focusing Lenses
The beam can be focused by inserting Beryllium compound refractive lenses in the beam path. The focal length can be adjusted for a given X-ray energy by selecting an appropriate number of individual lenses (up to 10) and stacking them. One can switch from one stack to another (up to three) remotely. Such a unit is located 4 meters upstream from the sample. The focusing unit has the capability to be translated longitudinally ±0.15 m. This allows some tunability in the beam size at the sample when not working at the focus.
Harmonic Rejection Mirrors
![Harmonic Rejection Mirrors](/sites/default/files/styles/embed/public/2023-10/xpp_hr_mirrors.jpg?itok=_AJ5QQyG)
Local harmonic rejection is provided by two silicon mirrors located 1.9 and 2.4 m upstream the sample location. These also offer the possibility to provide the beam with a grazing angle to the sample. Both mirrors can rotate 360°, and can thus deflect the beam downwards of upwards depending on the required scattering geometry.
Laser in-coupling Box(LIB)
Diffractometer
![XPP Diffractometer](/sites/default/files/styles/embed/public/2023-10/xpp_diffratometer.jpg?itok=NRBR8gua)
A configurable diffractometer system is available at XPP. The system is capable of positioning a wide variety of sample environments with a platform setup. The top surface of the platform diffractometer is 400 x 400 mm2. The distance between the top surface of the diffractometer and its center or rotation is 230 mm nominal. The top stages of the platform may be replaced with a kappa diffractometer that may be more appropriate for positioning small samples over a wide angular range.
A robotic detector positioned is used to move various X-ray detectors to a desired location. This system has the capability of positioning the detectors over a spherical surface of radii ranging from 10-100 cm. The detector positioned may also be moved in a Cartesian coordinate system.
XPP Videos
A flyover view of the XPP instrument. For more XPP related videos, see the LCLS XPP playlist on YouTube.
Download animation (right click and save link as):
![](/sites/default/files/styles/centered/public/oembed_thumbnails/2023-10/3bc3gm_TMsfNGgv1WI41n5WJGWpUJl8gL13LRI0QZxM.jpg?itok=WZqUjPoL)
XPP | X-ray Pump Probe (XPP) Instrument
XPP CONTACT INFO
Takahiro Sato
Instrument Lead Scientist (Methodology/X-ray optics)
(650) 926-3749
takahiro@slac.stanford.edu
Diling Zhu
Scientist(Methodology/X-ray optics)
(650) 926-2913
dlzhu@slac.stanford.edu
Yanwen Sun
Scientist(XPCS/X-ray optics)
(650) 926-2562
yanwen@slac.stanford.edu
Roberto Alonso-Mori
Scientist (Spectroscopy)
(650) 926-4179
robertoa@slac.stanford.edu
Hasan Yavas
Scientist (IXS/RIXS)
(650) 926-3084
yavas@slac.stanford.edu
Matthias Hoffmann
Laser Scientist
(650) 926-4446
hoffmann@slac.stanford.edu
Adam White
XPP Area Manager
(650) 926-4778
adamwh@slac.stanford.edu
Daniel Stefanescu
XPP technical advisor
(650) 926-3662
daniel@slac.stanford.edu
Vincent Esposito
Controls and DAQ Engineer
(650) 926-3410
espov@slac.stanford.edu
Ying Chen
Mechanical Engineer
yingchen@slac.stanford.edu
Matthieu Chollet
Scientist
(650) 926-3458
mchollet@slac.stanford.edu
Control Room: (650) 926-1703
XPP Hutch: (650) 926-7463