ALSNews Vol. 212, November 27, 2002

ALSNews is a biweekly electronic newsletter to keep users and other interested parties informed about developments at the Advanced Light Source, a national user facility located at Lawrence Berkeley National Laboratory, University of California. To be placed on the mailing list, send your name and complete internet address to ALSNews@lbl.gov. We welcome suggestions for topics and content.

Previous Issues are available.

Dynamic Jan–Teller Effect in Buckyball Cations
DOE Secretary Spencer Abraham Visits ALS
First Light at Molecular Environmental Science Beamline
Four to Join UEC After Three-Way Tie in Vote
Last Call: General Sciences Proposals Due December 1
Wanted: Publications of ALS-Related Work, 2002
Who's in Town: A Sampling of ALS Users
Operations Update

1. DYNAMIC JAHN–TELLER EFFECT IN BUCKYBALL CATIONS
by Art Robinson
(Contacts: berrah@wmich.edu, yencha@albany.edu)

High symmetry is not always the attribute preferred by nature when it comes to the geometry of atoms in molecules and solids, where structural distortions can in certain circumstances lower the overall energy and make for a more stable, if less symmetric, configuration. The latest example comes from the ALS, where a multinational team from the United States, Finland, and Brazil has uncovered the first experimental evidence for a dynamic Jahn–Teller effect in isolated cations of C₆₀ ("buckyballs"). With an origin in a strong coupling between electronic and vibrational states, the Jahn–Teller effect results in a lowering of the icosahedral symmetry of the neutral cluster. From the valence photoelectron spectrum, the group was able to unambiguously identify the relaxed geometry of the ionic ground state and determine that it was different from that believed to hold in matrix-isolated ions.

Read the full story at http://www-als.lbl.gov/als/science/sci_archive/58buckyball.html.

Publication about this research: S.E. Canton, A.J. Yencha, E. Kukk, J.D. Bozek, M.C.A. Lopes, G. Snell, and N. Berrah, "Experimental Evidence of a Dynamic Jahn-Teller Effect in C₆₀⁺" Phys. Rev. Lett. 89, 045502 (2002).

2. DOE SECRETARY SPENCER ABRAHAM VISITS ALS

U.S. Secretary of Energy Spencer Abraham continued a tour of the Bay Area's three Department of Energy (DOE) laboratories yesterday with a visit to Berkeley Lab that included presentations at the ALS and an address to Berkeley Lab employees on the ALS patio. Berkeley Lab Director Charles Shank and ALS Director Daniel Chemla were on hand to escort Abraham, his wife, Jane, and a group including Ray Orbach (Director, DOE Office of Science) and Bruce Darling (University of California Vice President for University Affairs) around the ALS. Inside, Abraham listened appreciatively as Carolyn Larabell (Life Sciences Division) described recent advances in 3D tomography of single cells at Beamline 6.1.2 and as Daniel discussed molecular environmental science studies (for example, of magnesium oxide nanoparticles) that will be possible at the brand-new Beamline 11.0.2 (see item 3 below). The Secretary of Energy then presided over an informal ceremony launching the beamline's commissioning phase. Outside on the patio, Abraham spoke to a Berkeley Lab all-hands gathering, praising the Lab's past achievements and expressing his belief that "the best days remain in the future." In addition to his stop at Berkeley Lab, Secretary Abraham is also scheduled to visit Lawrence Livermore National Laboratory and the Stanford Linear Accelerator Center.

3. FIRST LIGHT AT MOLECULAR ENVIRONMENTAL SCIENCE BEAMLINE
(Contacts: a T_Warwick@lbl.gov, DKShuh@lbl.gov)

Beamline 11.0.2, equipped with an elliptically polarizing undulator (EPU) for molecular environmental science (MES) experiments, received synchrotron light for the first time on October 30, 2002. On that day, the undulator beam was brought to the endstation areas within two hours after the completion of readiness reviews. The first absorption spectra were obtained the following day, and the first soft x-ray microscopy images were obtained the day after that. Careful tune-up will proceed in the weeks to come, along with commissioning of the user endstations, with the synchrotron radiation beam serving a limited number of preliminary user experiments. The ALS-MES project is a collaboration with Berkeley Lab's Chemical Sciences Division, with the beamline designed by the ALS Experimental Systems Group and the 5-cm-period EPU designed by the ALS Engineering Group. David Shuh (Chemical Sciences Division), is the MES project leader.

The entrance-slitless, collimated, plane-grating monochromator builds on optical designs first implemented at the BESSY synchrotron facility in Berlin. The optical elements (monochromator and mirrors), built for high performance, low contamination, and ease of operation, are based on new designs and were built by the ALS Engineering Group.The beamline has two branchlines that diverge after the monochromator. One branch has been designed and optimized for use with a scanning transmission x-ray microscope (STXM), while the other branch has a rotating platform specifically developed to support endstations that will perform x-ray absorption, x-ray emission, and photoelectron spectroscopies. A major scientific theme of this MES facility is to investigate fundamental chemical, materials, and interfacial systems in the presence of water (or other high-vapor-pressure materials) to gain an understanding of the chemistry relevant to many important environmental systems.

The STXM was moved to this beamline from Beamline 7.0.1. The control and acquisition system was modified to be compatible with that used at the Beamline 5.3.2 STXM. After preliminary alignment of the STXM at its new location, images of polymer-blend specimens were successfully acquired. Images were recorded in air at 370 eV with small exit slits using a silicon detector. Initial estimates of the photon flux at the STXM operating at 300 eV in air was about 5 x 10⁷ photons/s with a ring current of 250 mA (in helium the flux will be higher by a large factor). The first STXM image was collected over a large area with a reasonable dwell. Later images were recorded with high resolution and at a very fast scanning rate. These first images show that the combination of the modified STXM and the new branchline will be an exceptional tool for environmental, chemical, and materials sciences.

The rotating experimental platform serving the spectroscopy branchline is functional. Many of the beamline's performance characteristics (flux, resolution, and focusing properties) are currently being established in this branchline as well. The spectroscopy endstations occupying the respective platform wedge sections and the spectroscopic capabilities of these endstations will continue to be commissioned in the next few weeks using the characterized synchrotron radiation beam.

4. FOUR TO JOIN UEC AFTER THREE-WAY TIE IN VOTE
(Contact: AMGreiner@lbl.gov)

The ALS Users' Executive Committee (UEC) will welcome four new members next year, one more than had been anticipated. The top three vote-getters were to become the next UEC members, to replace the three members rotating off the committee at the end of 2002. When the votes were tabulated, however, three candidates ended up tied for "second place." All four will join the UEC next year. The incoming members are Gregory Denbeaux (Center for X-Ray Optics, Berkeley Lab), Dan Dessau (Dept. of Physics, University of Colorado), Keith Jackson (Center for X-Ray Optics, Berkeley Lab), and Gary E. Mitchell (Dow Chemical Company). More information about the new UEC members is available at http://www-als.lbl.gov/als/uec/vote/; for information about continuing members, see http://www-als.lbl.gov/als/uec/.

5. LAST CALL: GENERAL SCIENCES PROPOSALS DUE DECEMBER 1
(Contact: alsproposals@lbl.gov)

Sunday, December 1, 2002, is the deadline for general user proposals (formerly "independent investigator " proposals) in the general sciences for the running period from June to December 2003. (This deadline does not apply to protein crystallography proposals, which have a separate process and schedule; see the link for "Proposal process" below.) The User Services Office has sent email confirmations for all proposals received so far. If you submitted a proposal but have not received confirmation, please contact Jeff Troutman at alsproposals@lbl.gov.

Scientists wishing to renew a previous proposal must fill in a one-page Experiment Report/Beamtime Request (an RTF form is available for download at http://www-als.lbl.gov/als/quickguide/expt_report.rtf) and submit it to the User Services Office by the December 1 deadline. The numeric rating for each proposal will be communicated to the user along with any comments offered by the Proposal Study Panel. The cutoff rating for each beamline in the previous proposal cycle is published on the Web (see below). The following resources are available for further information:

Submitting a general science proposal for beam time
http://alsusweb.lbl.gov/

Becoming an ALS User
http://www-als.lbl.gov/als/quickguide/becomealsuser.html

Proposal process (general science and protein crystallography)
http://www-als.lbl.gov/als/quickguide/independinvest.html

Beamline information
http://www-als.lbl.gov/als/als_users_bl/datasheets.html
http://www-als.lbl.gov/als/als_users_bl/bl_table.html

Proposal Study Panel (PSP) scores
http://www-als.lbl.gov/als/quickguide/pspscores.html

ALS User Services Administrator
alsuser@lbl.gov

6. WANTED: PUBLICATIONS OF ALS-RELATED WORK, 2002
(Contact: alsuser@lbl.gov)

If you have recently published any ALS-related work in a scientific journal or conference proceedings, or completed a Ph.D. thesis on work done at the ALS, please let us know by going to the User Services Online Forms Web page at http://alsusweb.lbl.gov. Click on the "Publications Search & Submittal" link; this should remind you which of your publications are already in our database. Please DO NOT submit unpublished talks; abstracts; or journal articles that are still "submitted," "accepted," or "in press."

Your timely response will be greatly appreciated, as it is imperative that we accurately report the number of ALS-related publications to our funding agency. Publications are used as an important measure of the excellent science being done at our facility.

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

Following are some of the experimenters who will be collecting data during the next two weeks at the ALS.

Beamline 1.4.3
Sasa Bajt, John Bradley (Lawrence Livermore National Laboratory)

Beamline 4.0.2
Stephen Cramer (Univ. of California, Davis)

Beamlines 5.0.1, 5.0.2, 5.0.3
Marc Jacobs (Vertex Pharmaceuticals)
Wenqing Xu, Weijun Huang, Ye Zhu, Yi Xing, James Sampietro (Univ. of Washington)
Gyorgy Snell (Syrrx, Inc.)

Beamline 7.0.1
Marjorie Olmstead (Univ. of Washington)
James Tobin (Lawrence Livermore National Laboratory)
Joseph Nordgren (Uppsala Univ., Sweden)

Beamline 7.3.1.1
Cynthia Morin, Adam Hitchcock (McMaster Univ., Canada)

Beamline 8.0.1
James Tobin (Lawrence Livermore National Laboratory)

Beamline 8.3.1
Irina Krylova, Peter Hwang, Julien Chen, Srikanth Dakoji (Univ. of California, San Francisco)
Ernst Bergmann, Bart Hazes, Pawel Grochulski, Gerald Audette (Univ. of Alberta, Canada)

Beamline 10.0.1
Ron Phaneuf (Univ. of Nevada, Reno)
Dan Dessau (Univ. of Colorado at Boulder)

Beamline 10.3.2
Alain Manceau (Univ. Joseph Fourier, France)

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

For the user runs of October 29 - November 3 and November 15 - 18, the beam reliability (time delivered/time scheduled) was 97%. Of the scheduled beam, 94% 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/schedules/index.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.

ALSNews is a biweekly electronic newsletter to keep users informed about developments at the Advanced Light Source, a national user facility located at Ernest Orlando Lawrence Berkeley National Laboratory, University of California. To be placed on the mailing list, send your email address to ALSNews@lbl.gov. We welcome suggestions for topics and content. Submissions are due the Friday before the issue date.

LBNL/PUB-863
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.

ALSNews Vol. 212, November 27, 2002

Previous Issues are available.

Table of Contents