ALSNews Vol. 227, august 6, 2003
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.
Table of Contents
- Ultrafast XANES Technique Reveals Photochemical Transients
- 2003 ALS Users' Meeting Slated for October 6 - 8
- COLTRIMS Work Featured in Physics Today
- ALS Doctoral Fellowship Winners Announced
- Who's in Town: A Sampling of ALS Users
- Operations Update
1. ULTRAFAST XANES TECHNIQUE REVEALS PHOTOCHEMICAL
TRANSIENTS
by Art Robinson
(Contacts: christian.bressler@ipmc.unil.ch, majed.chergui@ipmc.unil.ch)
Ultrafast, time-resolved x-ray experiments are on the frontier of synchrotron radiation science with several demonstrations of white-light (Laue) x-ray diffraction to track structural changes on the picosecond time scale. Comparable experiments with x-ray absorption are more challenging because data must be recorded at each photon energy over the spectral range of interest. Transient, photochemical intermediate states in solution pose the additional difficulty of a solvent whose effects must be accounted for. A team of researchers from the University of Lausanne, the Swiss Light Source, the University of California, Berkeley, and the ALS have paved the way for experiments of this type by using x-ray absorption near-edge structure spectroscopy (XANES, also known as NEXAFS) to detect the change in oxidation state of the central ruthenium atom in a laser-excited ruthenium complex in solution.
Read the full story at http://www-als.lbl.gov/als/science/sci_archive/65photochemical.html.
Publication about this research: M. Saes, C. Bressler, R. Abela, D. Grolimund, S.L. Johnson, P.A. Heimann, and M. Chergui, "Observing photochemical transients by ultrafast x-ray absorption spectroscopy," Phys. Rev. Lett. 90, 047403 (2003).
2. 2003 ALS USERS' MEETING SLATED FOR OCTOBER
6 - 8
(Contact: alsum2003@lbl.gov)
The annual ALS Users' Meeting will be held at Berkeley Lab from Monday, October 6, through Wednesday, October 8, 2003. Along with the regular complement of keynote speakers, facility updates, highlights from young researchers, focused workshops, poster session, vendor reception, and awards banquet, this year's meeting will also celebrate the tenth anniversary of the ALS. Detailed information and online registration is now available at http://www-als.lbl.gov/als/usermtg/. Register by September 15 to receive an early registration rate of $150 (regular) or $60 (student). Discounted room rates at the nearby Hotel Durant will be available until September 27, 2003.
ALS users, postdocs, students, and staff are invited to submit abstracts online at http://www-als.lbl.gov/als/usermtg/abstracts.html. Highlight oral presentations will be selected from the submitted abstracts; others will be presented in the poster session. Abstracts must be received by September 8 to be considered for an oral presentation or the student poster competition. Abstracts received by September 22 are guaranteed space in the general poster session and inclusion in the program booklet.
Workshops for the second and third days of the meeting include the following:
- Applications of Variable Polarization in Soft X-Ray Microscopy and Spectroscopy
- Inelastic X-Ray Scattering and Ultra High Resolution Photoemission Studies of Strongly Correlated Systems
- Macromolecular Crystallography
- Molecular Environmental Sciences
- Recent Advances in Synchrotron-Based Microscopy
There will also be a joint ALS-SSRL workshop on Probing Mechanical Deformation and Failure via Synchrotron X Rays. For additional information about individual workshops, please contact the respective workshop organizer(s). Contact information is provided at http://www-als.lbl.gov/als/usermtg/workshops.html.
3. COLTRIMS WORK FEATURED IN PHYSICS TODAY
Cold-target recoil-ion-momentum spectroscopy (COLTRIMS) work done at the ALS by Timur Osipov et al. [Phys. Rev. Lett. 90, 233002 (2003)] is being featured this month in the Search and Discovery section of Physics Today. Headlined "Watching a Molecule Break Up Reveals How Quickly It Changes Shape," the article reports on the use of an innovative spectroscopic method to track and time how an acetylene molecule changes into its structural isomer, vinylidene. The COLTRIMS method involves splitting molecules into ionized fragments and analyzing the momenta of the various fragments in an applied electric field. It is a time-of-flight method that takes advantage of the "delayed" x-ray timing structure provided by two-bunch operation at the ALS. The technique was developed by a collaboration between groups from Kansas State University, Frankfurt University, Western Michigan University, and Berkeley Lab. In the experiment described in the article, the researchers deduced that it takes less than 60 femtoseconds to change doubly charged acetylene into vinylidene through the transfer of a hydrogen atom from one carbon atom to another. Previous COLTRIMS work by this collaboration was highlighted in ALSNews Vol. 189 (http://www-als.lbl.gov/als/science/sci_archive/46gasXPD.html).
4. ALS DOCTORAL FELLOWSHIP WINERS ANNOUNCED
(Contact: ZHussain@lbl.gov)
The ALS is extremely pleased to announce this year's winners of ALS Doctoral Fellowships: Yulin Chen (Stanford Univ., spin-resolved photoemission spectroscopy), Mohammad F. Gharaibeh (Univ. of Nevada, Reno, ion spectroscopy), Darcy S. Peterka (Univ. of California, Berkeley, photoionization and photoelectron imaging of nanodroplets), Daniel Rolles (Technical Univ. of Berlin, coherence and nondipole effects in the photoionization of oriented molecules), Zhe Sun (Univ. of Colorado, high-resolution photoemission and diffuse scattering), Joshua Turner (Univ. of Oregon, coherent soft x-ray magnetic scattering), and Feng Wang (Univ. of Michigan, photoemission and spectroscopy of correlated systems). These exceptional Ph.D. students have been selected to perform a major part of their thesis work at the ALS during a one-year appointment covering the 2003 - 2004 academic year. For Daniel and Zhe, this will be a continuation of their fellowship grants from last year. Congratulations to all seven! The selection committee consisted of Sam Bader (Argonne National Laboratory and ALS Science Advisory Committee Chair), Jennifer Doudna (Univ. of California, Berkeley, and ALS Users' Executive Committee Chair), Franz Himpsel (Univ. of Wisconsin), Zahid Hussain (ALS), and Neville Smith (ALS). Detailed information about the fellowships, along with links to frequently asked questions and the application form, can be found at http://www-als.lbl.gov/als/fellowships/index.html.
5. 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. (The ALS will be running in two-bunch mode August 12 through 24.)
Beamline 1.4.3
Dan Fried (Univ. of California, San Francisco)
Ted Raab (Carnegie Institution of Washington)
Beamline 4.0.2
Steve Cramer (Univ. of California, Davis, and Berkeley Lab)
Nora Berrah (Western Michigan Univ.)
Beamlines 5.0.1, 5.0.2, 5.0.3
Ernst Ter Haar (Vertex Pharmaceuticals)
Kevin Parris (Wyeth-Ayerst Research)
Ed Berry, Li-Shar Huang, Graciella Salerno (Berkeley Lab)
Latesh Lad, Jonathan Friedman (Univ. of California, Irvine)
Armando Villasenor, Mark Knapp (Roche Bioscience)
Xueyong Zhu, Xiaoping Dai (The Scripps Research Institute)
Daniela Bumbaca, Mark Jedrzejas (Children's Hospital Oakland Research
Institute)
Beamline 5.3.1
Harald Ade (North Carolina State Univ.)
Gary Mitchell (The Dow Chemical Company)
Adam Hitchcock (McMaster Univ., Canada)
Beamline 7.0.1
Marjorie Olmstead (Univ. of Washington)
Laurent Duda (Uppsala Univ., Sweden)
Beamline 7.3.1.1
Jo Stohr (Stanford Synchrotron Radiation Laboratory)
Andreas Scholl (Berkeley Lab)
Beamline 8.0.1
Maria Novella Piancastelli (Univ. of Rome)
Dennis Lindle (Univ. of Nevada, Las Vegas)
Beamlines 8.2.1, 8.2.2
Ailong Ke (Univ. of California, Berkeley)
Christopher Garcia, Marty Boulanger (Stanford Univ.)
Joseph Mougous (Univ. of California, Berkeley)
Jonathan Caruthers, David McKay (Stanford Univ.)
Beamline 8.3.1
Tom Lee (Univ. of California, San Francisco)
Adrian Keatinge-Clay (Univ. of California, San Francisco)
Ernst Bergmann, Craig Garen (Univ. of Alberta, Canada)
Anton Vila-Sanjurjo (Univ. of California, Berkeley)
Kam Zhang, Graeme Card (Plexxicon, Inc.)
Matt Good (Univ. of California, Berkeley)
Ho-Leung Ng (Univ. of California, Berkeley)
Geoffrey Facer, Shelley Godley (Fluidigm Corporation)
Stephanie Wang, Rick Huang (Univ. of California, San Francisco)
Eugene Hur (Univ. of California, San Francisco)
Beamline 9.0.2
Terrill Cool (Cornell Univ.)
Tomas Baer (Univ. of North Carolina)
Beamline 9.3.2
Nasser Hamdan (The American University of Sharjah, United Arab
Emirates)
Mohamed Faiz (King Fahd University of Petroleum
and Minerals, Saudi Arabia)
Felix Requejo (Berkeley Lab)
Simon Mun (Berkeley Lab)
Beamline 10.0.1
Nora Berrah (Western Michigan Univ.)
Z.X. Shen (Stanford Univ.)
Beamline 10.3.2
Daniel Grolimund (Paul Scherrer Institut, Switzerland)
6. OPERATIONS UPDATE
(Contact: Lampo@lbl.gov)
For the user runs of July 8 - 13, 16 - 21, 22 - 28, and July 30 - August 3, the beam reliability (time delivered/time scheduled) was 97%. Of the scheduled beam, 90% 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 (ALS-CR@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. A Web page showing the ring status in real time can be found at http://www-als.lbl.gov/als/status/.
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-875
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.