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In this issue:
ILC's High-Energy Collisions Require Accurate Energy Measurements
symmetry Logbook: The Blue Book
Radiological Work Permit and GERT Policies to Change

SLAC Today

Friday - June 29, 2007

University of California, Berkeley, student Erik Petigura (left) and Alexey Lyapin of University College London stand by components of the energy spectrometer in End Station A.

ILC's High-Energy Collisions Require Accurate Energy Measurements

The International Linear Collider (ILC) collaboration proposes to crash electron and positron beams together with a total energy of 500 GeV (billion electron volts). The actual energy of each beam will vary slightly from one bunch of particles to the next, so just before the collision point, energy spectrometers will measure each bunch's exact energy.

"We need to be able to measure the beam energy with an accuracy of one part in 10,000 to establish the masses of the new particles we'll hopefully see," said Yury Kolomensky, associate professor of physics at the University of California-Berkeley.

Kolomensky and his collaborators (from SLAC, the University of California, Berkeley, and the University of Notre Dame in the U.S.; University College London, Royal Holloway College, and Cambridge University in the U.K.; DESY in Germany; and Dubna in Russia) have installed their prototype energy spectrometer on the beam line in End Station A. For most of July, a test beam of electrons will whiz down the beam line, letting Kolomensky and others test equipment under ILC-like conditions. The energy of the test beam is about ten times less than that of an ILC beam, but has the same bunch length and charge.  Read more...

symmetry Logbook:
The Blue Book

(Photo - Blue book)
The SLAC Blue Book

Affectionately known at SLAC as simply The Blue Book, The Stanford Two-Mile Accelerator has been a classic on site since the day it was published in 1968. Shepherded into existence by an editorial committee of four SLAC staff members led by Richard B. Neal, the massive 1169-page, more-than-ninety-author treatise thoroughly documents all facets of the two-mile-long linear accelerator, or linac.

The blue clothbound book was conceived upon the realization that the staff working long and hard on the project would inevitably disperse upon the linac's completion. As a means of preservation, the volume was created to provide a systematic presentation of the knowledge and experience gained in the linac's design and construction.

The editorial committee divided the material into 27 chapters covering all aspects of the site, including buildings and utilities, as well as the components and systems of the accelerator and the beam switchyard. The SLAC linac is the longest linear accelerator in the world, and aspects of its design continue to be of interest not only to SLAC staff, but also to a wide range of accelerator designers, users, and builders.

The page reproduced here is from an author's proof of the book, currently being held in the collections of the SLAC Archives and History Office. Since the excerpt is from a true "blue-line" proof, this particular copy is blue both inside and out.

Click here to read this article in symmetry magazine.

Radiological Work Permit and GERT Policies to Change

Click on diagram for larger version.

Starting July 1, SLAC will have a new process for issuing Radiological Work Permits (RWPs), and a new requirement for General Employee Radiological Training (GERT) workers who want to enter unescorted into Radiation Areas.

RWPs—formal permits required by the Department of Energy—inform workers of radiological conditions and protective clothing they need to wear. RWPs are vital to SLAC's successful efforts to keep radiation doses as low as reasonably achievable (ALARA).

This new RWP will provide more detail about the work to be done and will require more supervisor involvement in radiological work planning. The revised RWP procedure details this new process.

RWPs only are required for entry or work inside Radiological Areas (as shown in the diagram above).

The new policy also requires that anyone entering a Radiological Area have at least Radiation Worker Training I (RWT I). For workers with GERT training, the new policy means that they can no longer enter a Radiation Area (which is one type of Radiological Area) without a properly trained escort.

RWPs are not required for those portions of Radiologically Controlled Areas (RCAs) that are outside of Radiological Areas. These non-Radiological-Area portions of RCAs require only GERT training for entry or work.

Please call Jim Allan at x4064 or Field Operations at x4299 if you have any questions about these changes.

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