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An Office of Science User Facility

Soft X-ray Materials Science (SXR)

This site is OBSOLETE as of 30 Oct. 2017
Please go to the new SXR site


End Stations

Electron Beam Ion Trap (EBIT) End Station

EBIT End Station

The Electron Beam Ion Trap (EBIT) endstation, outlined in the figures, is a system dedicated to the investigation of the interaction of light with dilute clouds of trapped highly charged ions (HCI). It is especially designed to explore the interaction of photons with highly charged ions in any desired charge state. Such ions are ubiquitous in astrophysics and high temperature plasmas, and have also important applications for studies of fundamental interactions.

Scientific goals include: The determination of photoionization and photoabsorption cross sections, both of utmost importance for astrophysics; the production, trapping and investigation of photoionized samples of strongly correlated warm, dense plasmas, this point representing one of the forefront topics of present plasma physics research; the direct photo-excitation of low-lying nuclear levels, which would imply a significant advance in nuclear physics. Precision measurements on the electronic level structure of HCIs shall be performed to test fundamental theories (QED) and parity non-conservation in the neutral currents sector. Future work will also aim at the preparation and control of highly excited coherent quantum states with combined XFEL and optical lasers.

The endstation consists of a fully operational EBIT. It is equipped with various spectrometers for visible, VUV, X-ray or fluorescence photon detection, including an X-ray microcalorimeter. Eight ports transverse to the LCLS beam give access for intense lasers into the trap region as well as for injecting gaseous targets. One axial port permits ion/photoion extraction and charge analysis of the extracted ions on a position-sensitive detector. The complete endstation requires ~4 x 2 m2 floor space and weights about 2 tons. It is further equipped with diagnostic tools to guarantee the overlap between the LCLS beam with the ion cloud and to measure the photon beam energy in a pulse-by-pulse mode. The present transportable EBIT endstation operation has been tested at the soft x-ray free electron laser FLASH, as well as at the BESSY II and PETRA III synchrotrons. The collaboration intends to develop and commission a new, dedicated user EBIT endstation for LCLS after the initial experimental phase.

Contact Information
Name: José R. Crespo López-Urrutia
Title: EBIT Group Leader, Max-Planck-Institut für Kernphysik, Heidelberg
Phone: +49 (0) 6221 516 521

Name: Peter Beiersdorfer
Title: Atomic Spectroscopy Group Leader, LLNL
Phone: (925) 423-3985


Technical Specifications
Technique Electron Beam Ion Trap
Flourescence detection
Photoion counting

Detector X-ray Ge spectrometer
VUV grating spectrometer
Photoion velocity filter
Position sensitive photoion detector

Sample Highly charged ions starting from atomic beams

Control Electron beam energy, trapping time, extraction parameters
Ion-photon overlap

SLAC SLAC National Accelerator Laboratory, Menlo Park, CA
Operated by Stanford University for the U.S. Dept. of Energy