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.7           December 13, 1994

Table of Contents


    1. SINCE YOU ASKED
    2. OPERATIONS OVERVIEW  
    3. SCINTILLATING SUBJECTS
    4. TIMELY TOPICS

1. SINCE YOU ASKED
No - you are not the only devotee of ALSNews. We now have over 400 subscribers in 19 different countries.

2. OPERATIONS OVERVIEW
(contact: rmmiller@lbl.gov)

Maintenance time will be two days per week during December, to minimize the time required for the January shutdown by completing some tasks early. User shifts have been scheduled on weekends to compensate for the additional maintenance days.

Operations for Wednesday, Dec. 14, through Friday, Dec. 30:
Standard 320 bunch, 400 mA operation for users:
    Dec. 15-18, 00:00-24:00
    Dec. 19, 00:00-08:00 and 12:00-24:00
    Dec. 20, 00:00-24:00 
    Dec. 21, 00:00-16:00
Maintenance and startup:  
    Dec. 19 (08:00-12:00), 22, 23
Accelerator physics (Wednesdays): 
    Dec. 14, 00:00-24:00
    Dec. 21, 16:00-24:00
Holidays: Dec. 24-Jan. 2

Shutdown for new equipment installations begins January 3, 1995. User operations are scheduled to resume on February 22, 1995.

3. SCINTILLATING SUBJECTS

**WORKSHOP EXPLORES PERMANENT-MAGNET STORAGE RING POSSIBILITIES**
(contact: bertsche@fnal.gov)

Twenty-six experts in the fields of permanent magnets and storage rings met at LBL, November 14-16, to discuss the feasibility of building two storage rings using permanent magnets in the new Fermilab Main Injector Tunnel, with the aim of enhancing the U.S. High Energy Physics hadron program. The Workshop on Permanent Magnet Storage Rings attracted participants from LBL, Fermi National Accelerator Laboratory, Stanford Linear Accelerator Center, U. of Michigan, Technical Research Center of Finland, and two private companies. By the end of the workshop they were very enthusiastic about the proposal, having accomplished a great deal of design work in a short time and having concluded that it appears feasible to build both rings using permanent magnet techniques.

The first new storage ring, the "Recycler Ring," would accumulate antiprotons at about 40 GeV/c from the Accumulator and re-use the antiprotons remaining at the end of a Tevatron store. The "Stacker Ring" would accumulate protons at around 9 GeV/c from the Booster prior to acceleration in the new Main Injector. Workshop participants developed magnet parameters and quadrupole tuning range requirements for the rings based on Fermilab's Main Injector lattice. They calculated magnet aperture requirements from both beam dynamics and vacuum considerations, chose permanent magnet materials (ferrite ceramic) for their designs, and discussed magnetic measurement techniques for both the magnet blocks and the finished magnets. They also determined that the required magnets would fit in the available tunnel space and that the technology is sufficiently mature for the research and development required to be within normal engineering bounds.

The major motivations for building permanent-magnet storage rings are the high reliability of permanent magnets (conventional storage rings are vulnerable to antiproton loss due to power glitches, after which it can take days to re-accumulate the antiprotons) and their low cost. The costs are at least a factor of three smaller than the direct cost of conventional dipoles with similar parameters, even before taking into account the costs of power supplies, cabling, controls, low-conductivity water systems, safety systems, etc. for the conventional systems.

**MONOPODS SIMPLIFY ALS SURVEY & ALIGNMENT**
(contact: bill_baldock@macmail.lbl.gov)

One seldom walks around the ALS experiment floor these days without seeing one or more monopods: these tall, cylindrical objects are being used by ALS survey and alignment crews to determine the exact locations of reference points in the ALS floor, known as monuments and marked by precisely beveled holes in the floor. Once complete, the monument survey will be the basis for survey and alignment of storage ring and beamline equipment. Monopods were devised at the ALS as a means of decreasing the time required for monument surveys while increasing measurement accuracy. The largest part of a monopod is a cylinder of carbon fiber, chosen for its low coefficient of thermal expansion. An adjustable tripod assembly supports this cylinder upright. At the monopod's bottom end is a beveled cup designed to rest on a sphere placed in a monument. The top end of the monopod has an adapter used to mount any of several surveying instruments or targets.

The advantage of using a monopod as a base for surveying instruments derives from the need to know the height of the surveying tool as exactly as its horizontal position. The monopod's height is a known constant, so the additional sightings once used to determine an instrument's height are no longer necessary; ALS surveyors get the height of their instruments "for free."

The monopod was conceived by Bill Baldock and developed by Robert Duarte, Ted Lauritzen, Richard DeMarco, and Gary Krebs (all of the ALS).

**ALS IN THE NEWS**
(reference: Andrew Lawler, "White House Ponders Increase for DOE Labs," Science, Vol. 266, pp. 963-964.)

ALS Director Brian Kincaid was quoted in the November 11 issue of Science Magazine in an article describing a Clinton Administration "rescue" plan under consideration which would pump an additional $200 million into the operating funds of Department of Energy user facilities for FY96. The plan would extend operating schedules for facilities such as the ALS, which is now operating at only three-fifths capacity because of present funding levels. In the article, Kincaid said that a $2-million boost in ALS's $22-million budget would let the ALS run for a full 5000 hours in FY96, meaning 16 user shifts per week instead of only 9 as is the current operations schedule.

4. TIMELY TOPICS

**JAN-FEB SHUTDOWN INFORMATION**
(contact: rmmiller@lbl.gov)

A shutdown for large-scale equipment installation will be held from January 3 to February 17, 1995. The last user shift before the holidays and shutdown will be day shift on December 21 and the first scheduled user shift after the shutdown is swing shift on February 22, 1995. During the shutdown, engineers will remove the 5-cm-period undulator on beamline 7.0 and change its vacuum chamber to allow a minimum gap of 14 mm (down from 23 mm), increasing the beamline's available photon energy range. Other plans include front-end connections for Beamline 7.3, mirror installation for branchline 9.0.2, improvements to the rf system, and replacement of the linac filament.

Writers: jccross@lbl.gov, deborah_dixon@macmail.lbl.gov