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.

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ALSNews           Vol. 44           January 24, 1996

Table of Contents


    1. OPERATIONS UPDATE
    2. NEXT SHUTDOWN DATE ANNOUNCED
    3. LONG-TERM SCHEDULING MEETING
    4.  INFRARED SPECTROMICROSCOPY BEAMLINE
    5. ALS PUBLICATIONS LIST AVAILABLE
    6. 28 INDEPENDENT INVESTIGATOR PROPOSALS RECEIVED

1. OPERATIONS UPDATE
(contact: rmmiller@lbl.gov)

Beam availability for the last two weeks was 86.7% overall and 89.3% during user shifts. Lost beamtime was primarily due to a vacuum leak on the Beamline 8.0 personnel safety shutter (repaired), failure of an anode tube in the storage ring rf system (replaced), and failure of a variable-flow motorized water valve (repaired).

Operations Summary for January 24 - February 12

Jan 24, 00:00-08:00           User Scrubbing & Special Operations
Jan 24, 08:00- Jan 29, 07:15  1.5-GeV/400-mA/320-bunch user operations
Jan 29, 07:30-24:00           Maintenance & Startup
Jan 30, 00:00-24:00           Accelerator Physics
Jan 31, 00:00-08:00           User Scrubbing & Special Operations
Jan 31, 08:00- Feb 05, 07:15  1.9-GeV/260-mA/320-bunch user operations
Feb 05, 07:30-24:00           Maintenance & Startup
Feb 06, 00:00-24:00           Accelerator Physics
Feb 07, 00:00-08:00           User Scrubbing & Special Operations
Feb 07, 08:00- Feb 12, 07:15  1.5-GeV/400-mA/320-bunch user operations

** SPECIAL OPERATIONS USER SHIFT **
Reminder to users: the Wednesday owl shift (00:00-08:00) is designated a special operations request shift for users to request special operating conditions such as scrubbing beam, lower-energy operation, different bunch modes, etc. If there are no requests for special operations or scrubbing, the shift for that week will default to the planned energy/fill pattern scheduled for the remainder of that week. Requests for scrubbing beam should be sent to Bob Miller [email: rmmiller@lbl.gov, phone: (510) 486-4738] no later than the scheduling meeting on the Friday before. Other requests for special operations should be sent to Bob at least one week in advance of the shift requested.

2. NEXT SHUTDOWN DATE ANNOUNCED

The next machine shutdown for major equipment installation and maintenance work will start on Monday, April 15. The shutdown is scheduled to last four weeks, with machine startup slated for the week of May 13 and the first user operations shift for May 22. The primary shutdown activity is the installation of the new wiggler (designated W16) in sector 5 for the protein crystallography beamline. The wiggler will bring the in-the-ring insertion device total to five (out of a possible ten). Other installations will include the front ends for the infrared beamline (Beamline 1.4) and the crystallography beamline (Beamline 5.0).

3. LONG-TERM SCHEDULING MEETING
(contact: fred_schlachter@lbl.gov)

ALS management met with the ALS Users' Executive Committee and with users on January 19 to discuss the schedule for May - September, 1996. (The fall shutdown will begin in mid-September or later.) The operating schedule for this period will be finalized in the coming weeks. When it is complete, the schedule will be sent to all current and scheduled ALS users and will appear in ALSNews.

Users who have specific requests for scheduling during this period should send them to Fred Schlachter (email: fred_schlachter@lbl.gov; fax: 510-486-6499) by January 29 at 8:00 a.m. (California time).

Users who have experiments demanding 400-mA operation at 1.9 GeV should contact Fred by the same January 29 deadline. To deliver 1.9-GeV/400mA operation would require several down-days for rf systems tests before the start of the April-May shutdown; this will not be done unless there is substantial demand for these operating conditions.

4. INFRARED SPECTROMICROSCOPY BEAMLINE
(contact: wrmckinney@lbl.gov)

The ALS is developing a beamline for infrared spectromicroscopy based on the strong desire expressed by the scientific community for such a facility. Design and construction is underway with initial operation scheduled for fall 1996. Infrared spectroscopy has been a mainline analytical tool for decades, both in industry and in the laboratory, owing to its ability to identify molecular constituents of complex materials from their vibrational spectra (molecular fingerprints). In the last decade, advanced optics and detectors have made spatially resolved infrared spectroscopy (spectromicroscopy) a popular technique for the analysis of inhomogeneous samples and small particles.

Infrared spectromicroscopes have been limited in resolution because of the low brightness of black-body sources. Synchrotron radiation, in contrast, is a very bright source of infrared radiation. For example, the ALS beamline will be at least 1000 times brighter than a black-body source over the frequency range of 300 cm [-1] to 5000 cm [-1] (wavelength = 2-30 microns). This takes into account the properties of the ALS electron beam, diffraction, and the maximum acceptance for the ALS vacuum chamber.

The primary frequency range of the bend magnet beamline (designated Beamline 1.4) will be in the mid-infrared as this covers the spectral range where many materials have vibrational modes which provide a unique fingerprint for each compound and is an important region for semiconductor defect identification. The endstations include an FTIR and IR microscope. Other beamlines in the future will extend the range to longer wavelengths.

The use of synchrotron radiation in infrared spectromicroscopy has already extended the basic technique to new levels of performance and resolution for molecular characterization of materials. Some of the many applications include adsorbate/substrate vibrations, films and crystals of high Tc superconductors, chemistry of polymer laminates (e.g., photographic film emulsions) and composites, analysis of trace evidence in forensics, and high pressure phases of microscopic samples in planetary physics research.

5. ALS PUBLICATIONS LIST AVAILABLE
(contact: alsuser@lbl.gov)

A list of journal articles, conference papers, and general publications related to the ALS and written by users and ALS staff is now available from the User Office. The list is also posted on the bulletin board in Building 6 near the lobby entrance to the experiment floor. To request a publication on the list, please contact Sharon Fujimura [phone: (510) 486-4991, email: alsuser@lbl.gov] and indicate the publication's ID number.

6. 28 INDEPENDENT INVESTIGATOR PROPOSALS RECEIVED

The ALS received 28 independent investigator proposals in the last submission period which ended in December. This represents a substantial increase over the previous submission cycle and indicates the growing demand for access to the ALS research facility. The proposals will now undergo peer review by the Program Study Panel which rates the proposals and makes recommendations on the requisite beamtime. Highly rated proposals will be allocated beamtime between May and September by the ALS Scientific Program Head, Neville Smith, in consultation with PRT spokespersons.