1. ELECTRONIC STRUCTURE OF CMR OXIDES
by Art Robinson
(Contact: dessau@spot.colorado.edu)

Complex (or correlated-electron) materials are on the frontier of materials physics because conventional solid-state theory is often unable to explain their frequently novel behavior, high-temperature superconductivity being a prime example. Among these materials are the manganese oxide compounds that exhibit the colossal magnetoresistance (CMR) effect. An American-Japanese collaboration working at the Advanced Light Source has now shown that the quasiparticle concept, a pillar of current solid-state theory, does retain its validity in CMR oxides, but the peculiarities of the electronic structure result in rapid fluctuations at the nanometer length scale of separate conducting and insulating phases, fluctuations that appear to underlie the CMR effect.

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

Publication about this research: Y.-D. Chuang, A.D. Gromko, D.S. Dessau, T. Kimura, and Y. Tokura, "Fermi Surface Nesting and Nanoscale Fluctuating Charge/Orbital Ordering in Colossal Magnetoresistive Oxides," Science 292, 1509 (2001).

2. CALL FOR ABSTRACTS: 2001 ALS USERS' MEETING
(Contact: alsabstract@lbl.gov)

The ALS Users' Meeting Program Committee invites ALS users, including students and postdocs, to submit abstracts for oral or poster presentations to be presented at the annual Users' Meeting, which will be held at Berkeley Lab on October 15-17, 2001. Abstracts can be submitted online at http://www-als.lbl.gov/als/usermtg/abstracts.html. Submission deadlines are as follows:

• September 10, 2001
  - to be considered for an oral presentation and/or the student poster competition
• October 3, 2001
  - to guarantee a space in the poster session and be included in the program booklet
• October 10, 2001
  - for space in the poster session on an "as available" basis

Oral presentations for the "junior researchers" and "science highlights" sessions will be selected by the committee from the abstracts received; other submissions will be presented as posters. The poster session (including the student poster competition) will be held in conjunction with a reception and buffet dinner on Tuesday, October 16. Information about the meeting program, speakers, registration, and accommodations will be posted at http://www-als.lbl.gov/als/usermtg/ as soon as it becomes available.

3. T-SHIRT CONTEST ENDS AUGUST 1
(Contact: EJMoxon@lbl.gov)

You tumble out of bed, tired and groggy from a long night spent at the beamline collecting data. You have a few hours yet to grab a bite to eat and then get back up the hill for more of the same. What a comfort it is to slip into that 2001 ALS Users' Meeting t-shirt with the eye-catching logo that looks and feels great no matter what condition the rest of you is in! The ALS Users' Meeting T-Shirt Contest is open to anyone with an imagination, and there is no limit to the number of entries one can submit. T-shirt designs should be no larger than 8.5 by 11 inches (22 cm by 28 cm) and the words "Advanced Light Source" or "ALS" must appear somewhere in the design. Rough drawings or concepts, as well as more polished artwork, are all acceptable.

Send your designs by August 1 to

Elizabeth Moxon
Advanced Light Source
Berkeley Lab, MS 4-230
Berkeley, CA 94720
Fax: (510) 495-2111

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

The ALS UEC met on July 11. Part of the meeting included a presentation and discussion with Yves Petroff, former director of the European Synchrotron Radiation Facility (ESRF) who is now on sabbatical at the ALS. Yves has been asked by ALS management to look at the scientific program and operation of the ALS and all its beamlines. Yves's recommendations and findings will be important and will hopefully contribute to making the ALS even more efficient and productive than it already is. A useful dialogue between him and the UEC and even more so between him and all users and beamline scientists is important. I encourage all users to discuss issues regarding their beamline or experiments at an appropriate and opportune time with Yves.

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.

Beamline 1.4.3
Kelly Knutsen (Univ. of California, Berkeley)
Hoi-Ying Holman (Berkeley Lab)
Upal Ghosh (Stanford Univ.)
Felicia Betancourt and Bob Glaeser (Univ. of California, Berkeley, and Berkeley Lab)

Beamline 6.3.1
Hisanobu Wakita (Fukuoka Univ., Japan)
Ron Tackaberry (Berkeley Lab)

Beamline 7.0.1
Jim Tobin (Lawrence Livermore National Laboratory)
Shirley Chiang (Univ. of California, Davis)
George Wadill (Univ. of Missouri-Rolla)
Adam Hitchcock (McMaster Univ., Canada)
Harald Ade (North Carolina State Univ.)

Beamline 7.3.1.1
David Abraham (IBM T.J. Watson Research Center)
Simone Anders (IBM Almaden Research Center)
Boris Sinkovic (Univ. of Connecticut)

Beamline 7.3.3
Yang Mo Koo, Hyungdon Joo, Jaesong Kim (Pohang Univ., South Korea)
Ersan Ustundag (California Institute of Technology)

Beamline 8.0.1
Nora Berrah (Western Michigan Univ.)
Satish Myneni (Princeton Univ.)
Glenn Waychunas (Berkeley Lab)

Beamline 9.0.2
Jinian Shu (Berkeley Lab)
Rainer Dressler (Air Force Research Laboratory)

Beamline 10.0.1
Dan Dessau (Univ. of Colorado at Boulder)
Erwin Poliakoff (Louisiana State Univ.)

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

For the user runs of June 20 - 25, June 26 - July 1, July 3 - 9 (two-bunch mode, except July 4 holiday), and July 10 - 15 (two-bunch mode), the beam reliability (time delivered/time scheduled) was 94%. Of the scheduled beam, 90% was delivered to completion without interruption. There were two significant outages: on July 3, repair of a gradient power supply cost two shifts (17.7 hours), and on July 14, repair of the Beamline 9.3.1 hutch interlock cost 7.5 hours.

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.