1. MORE TROUBLE FOR THE DIPOLE APPROXIMATION
by Art Robinson
(Contact: lindle@nevada.edu)

A multi-institutional collaboration comprising both theorists and experimentalists working at the ALS has made the first measurements of second-order nondipole effects in the angular dependence of the cross section for neon valence photoemission. The finding potentially applies to a wide variety of x-ray photoemission studies, including gas-phase, surface-science, and materials-science work, where researchers may now need to account for the influence of higher-order nondipole terms beyond the standard dipole approximation conventionally applied to the interaction of x rays with matter.

Read the full story at http://www-als.lbl.gov/als/science/sci_archive/dipole_approx.html.

Publication about this research: A. Derevianko, O. Hemmers, S. Oblad, P. Glans, H. Wang, S.B.Whitfield, R. Wehlitz, I.A. Sellin, W.R. Johnson, D.W. Lindle, "Electric-Octupole and Pure-Electric-Quadrupole Effects in Soft-X-Ray Photoemission," Phys. Rev. Lett. 84, 2116 (2000).

2. ALS/SSRL MEETINGS FOSTER CLOSER TIES
(Contact: ZHussain@lbl.gov)

Representatives of the ALS and Stanford Synchrotron Radiation Laboratory (SSRL) management teams are scheduled to meet today at SSRL to discuss coordination and cooperation between the two light sources. Efforts will be made to coordinate scheduled installation shutdowns of the two facilities in an attempt to ensure the uninterrupted availability of x rays to researchers on the West Coast. Common areas of interest--such as detector development, highly correlated materials, and x-ray crystallography--will be identified, and possible areas for consolidation of efforts will be discussed. This meeting will be the second of many anticipated between the two management teams in an attempt to foster closer ties between the two facilities.

3. BEAMLINE 12.0.1 TO RECEIVE NEW SPECTROSCOPY ENDSTATION
(Contacts: dessau@colorado.edu, ZHussain@lbl.gov)

A new angle-resolved photoemission spectroscopy experimental endstation is being installed on Beamline 12.0.1, replacing MAXIMUM, which will be retired after many years of service. MAXIMUM, one of the first photoelectron microscopes, was initially installed on the Aladdin storage ring in Wisconsin before being moved to the ALS soon after the ALS became operational. The new photoemission experimental endstation will utilize a Scienta SES-100 analyzer. A new 1200-lines/mm variable-line-spacing grating monochromator will allow the beamline to operate with a resolving power of over 10,000. Also, new refocusing optics will be installed in the beamline to provide suitable focusing for the experiments. Alexei Federov, a postdoc with Dan Dessau (Univ. of Colorado at Boulder), is leading the effort to assemble the experimental apparatus. This endstation will expand the ability of the ALS to serve the large community of x-ray photoemission users on Beamlines 7.0.1, 8.0.1, and 10.0.1, as well as further increase the utilization of Beamline 12.0.1.

4. UEC CORNER: NOTES FROM THE USERS' EXECUTIVE COMMITTEE
by Harald Ade
(harald_ade@ncsu.edu)

The UEC election results have been certified and I am pleased to announce the winners: Jennifer A. Doudna (Howard Hughes Medical Institute and Department of Molecular Biophysics and Biochemistry, Yale University), Dennis W. Lindle (Department of Chemistry, University of Nevada, Las Vegas), Gerry McDermott (Physical Biosciences Division, Berkeley Lab), and student/postdoc member Aaron M. Covington (Department of Physics, University of Nevada, Reno).

These four new members will serve on the UEC for three years, rotating off in 2003. They will join continuing UEC members Rupert Perera (Berkeley Lab), Roger Falcone (Univ. of California, Berkeley), Lewis Johnson (Florida A&M Univ. and Berkeley Lab), Carolyn Larabell (Univ. of California, San Francisco, and Berkeley Lab), Cheuk-Yiu Ng (Iowa State Univ. and Ames Laboratory), past chair Nora Berrah (Western Michigan Univ.), and chair Harald Ade (North Carolina State Univ.). Many thanks to retiring members Stephen Kevan (Univ. of Oregon), Charles Fadley (Univ. of California, Davis), James Underwood (Berkeley Lab), and former student member David Hansen (Univ. of Nevada, Las Vegas). Congratulations to the election winners, and welcome to the UEC!

5. WHO'S IN TOWN: A SAMPLING OF ALS USERS

The ALS will be operating in two-bunch mode February 14-26. Following are some of the experimenters who will be collecting data during this time.

Beamline 4.0.1-2
Reinhard Doerner and colleagues (Univ. of Frankfurt, Germany)
Allen Landers (Western Michigan Univ.)
Timur Osipov (Kansas State Univ.)
Michael Prior (Berkeley Lab)

Beamline 5.3.1
Phil Heimann (Berkeley Lab)

Beamline 6.3.2
Eberhard Spiller (Univ. of Maryland, National Institute of Standards and Technology, Lawrence Livermore National Laboratory)

Beamlines 6.3.1, 8.0.1, and 9.3.1
Dennis Lindle (Univ. of Nevada, Las Vegas) and colleagues

Beamline 10.0.1
Nora Berrah and colleagues (Western Michigan Univ.)
Emma Sokell (Univ. College Dublin)

6. OPERATIONS UPDATE
(Contact: Lampo@lbl.gov)

For the user runs of January 30 - February 5 and February 6 - 11, the beam availability was 98%. Of the scheduled beam, 83% was delivered to completion without interruption. There were no significant outages. Long-term and weekly operations schedules are available on the Web (http://www-als.lbl.gov/als/accelinfo.html). Requests for special operations use of the "scrubbing" shift should be sent to Bruce Samuelson (BCSamuelson@lbl.gov, x4738) by 1:00 p.m. Friday. The Accelerator Status Hotline at (510) 486-6766 (ext. 6766 from Lab phones) features a recorded message giving up-to-date information on the operational status of the accelerator.

LBNL/PUB-848
Editors: lstamura@lbl.gov, alrobinson@lbl.gov, amgreiner@lbl.gov

This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.