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.


ALSNews           Vol. 98           March 18, 1998

Table of Contents


    1. NEW FOR USERS: CONVENIENT SUPPLY OF COMMONLY USED GASES
    2. CAL DAY REVISITS THE ALS ON APRIL 18
    3. WHO'S IN TOWN: A SAMPLING OF ALS USERS
    4. OPERATIONS UPDATE

1. NEW FOR USERS: CONVENIENT SUPPLY OF COMMONLY USED GASES
(contact: rkthatcher@lbl.gov)

A supply of the gases most commonly used at the ALS -- He, Ar, N2, and CO2 (large cylinders, standard purity), is now available for users in the gas storage racks by Building 6. Users may remove a bottle for use once they have signed for it in the Gas Log Book at the User Services Area and placed the tag from the bottle on the hook beside the log book. When filling out the Gas Log, users should include the following information: the date, their name and account number, the beamline or lab where the gas is to be used, the type of gas, and the quantity (number of bottles) taken. ALS staff will reorder additional cylinders based on this information and will maintain a readily available supply of common gases for all users.

All other standard industrial gas purchases can be ordered directly from an off-site vendor, Airgas. More information about ordering gases for experimental use at the ALS can be found in the ALS Quick Guide for Users.

2. CAL DAY REVISITS THE ALS ON APRIL 18
(contact: ejmoxon@lbl.gov)

On Saturday, April 18, the ALS and Berkeley Lab's Center for X-Ray Optics will welcome visitors to the ALS as part of the University of California's Cal Day Open House. Last year more than 300 people ventured up the hill to listen to talks and tour the ALS. Many enjoyed the opportunity to see science in action as they toured beamlines and spoke with scientists about their research. This year the public will again have a unique opportunity to learn about the ALS by touring the experiment floor, seeing examples of the research done here, and talking with scientists.

Visitors can board buses at the Hearst Mining Circle on the UC Berkeley campus at 11 a.m., 12 noon, 1 a.m., and 2 p.m. for a one-hour program including a talk and a tour of the ALS.

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

To highlight the richness of our user community and help introduce recent arrivals, we offer this listing of some of the experimenters who will be collecting data during the next two weeks at the ALS. Who's in Town is on the short side this week because of preparations for the Scientific Directions at the ALS workshop March 23-25 (see the Web site for the latest); we'll be back with more information in our April 1 issue.

Beamline 7.0.1: Sudipta Seal (U. Central Florida) will study heterogeneous interface formation in aluminum-titanium-carbon composites. Satish Myneni (Berkeley Lab) will investigate contaminant reactions at the bacteria-water interface.

Beamline 8.0.1: Sudipta Seal (U. Central Florida) will study the electronic structure of boron nitride-metal nitride interfaces.

Beamline 9.0.2.2: Cheuk-Yiu Ng, Matt Evans, and Stephanie Stimson (all of Iowa State University) and Gary Jarvis (Berkeley Lab) will continue their gas-phase pulsed-field ionization photoelectron spectroscopy of the ionic states of molecular oxygen (O2), nitric oxide (NO), carbonyl sulfide (OCS), and acetylene (C2H2).

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

Beam reliability for the last two weeks was 86.3% overall and 86.6% for user shifts. These percentages reflect outages caused by obstruction of the electron beam by two beam diagnostic devices on March 2. (See ALSNews Vol. 97 for more details.) Three user shifts were lost as a result of these problems. In addition, operations were interrupted unexpectedly on nine occasions during the last two weeks because of momentary pressure drops in the low-conductivity water system. A change in pump operation last Friday appears to have solved the problem.

On Monday at about 9 p.m., the klystron for section 2 of the linac failed. ALS staff diagnosed the problem yesterday and spent last night and today replacing the klystron tube. The new tube will be conditioned this evening, and the current estimate is that user beam will be restored after midnight tonight.

Long-term and weekly operations schedules are available on the Web (http://www-als.lbl.gov/als/als_ops/schedules/). Weekly operations scheduling meetings are held on Fridays at 3:30 p.m. in the Building 6 conference room. 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.