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SSRL Headlines Vol. 2, No. 9  March, 2002


Contents of This Issue:

  1. Science Highlight - Formation of Chlorinated Hydrocarbons in Weathering Plant Material
  2. Lab Directors of National Synchrotron Sources Meet to Discuss Issues and Opportunities of Common Interest
  3. Highlights of the Workshop on Recent Advances in the Medical Applications of Synchrotron Radiation
  4. SPEAR3 Update
  5. Upcoming Events at SSRL and Elsewhere
  6. User Research Administration Announcements

1.  Science Highlight - Formation of Chlorinated Hydrocarbons in Weathering
      Plant Material

      (contact: Satish Myneni, smyneni@princeton.edu)

Much attention has been given to ozone-depleting chlorofluorocarbons in the atmosphere, but little has been paid to the behavior of chlorine in soils. The widespread presence of potentially toxic organochlorine compounds in soils in both populated areas and unpolluted environments is cause for concern, more so because synthesized organochlorine compounds have long been used in agricultural and industrial applications, with the perception to date that we have benefited from these compounds. In recent studies using in-situ synchrotron-based x-ray absorption spectroscopy techniques on Beam Lines 6-2 and 2-3 at SSRL, Dr. Satish Myneni of Princeton University has documented the chemical states of organochlorine in soils and decomposing plant material. These studies indicate that organochlorine compounds form at rapid rates in natural systems and are the dominant form of chlorine in some weathering plant material. The chlorination of natural organic molecules plays an important role in the biogeochemical cycling of major and trace elements in the environment. This study shows a new insight into the Cl-cycle, which was never considered before.

More information regarding this research, including the reference to the recent publication in Science can be found at:

2.  Lab Directors of Four DOE Synchrotron Facilities Meet to Discuss Issues and
      Opportunities of Common Interest

      (contact: Keith Hodgson, hodgson@ssrl.slac.stanford.edu)

The directors of the four DOE synchrotron facilities (Daniel Chemla, ALS; Murray Gibson, APS; Steven Dierker, NSLS; Keith Hodgson, SSRL) met on Wednesday, March 13. A variety of topics were discussed, including how to best present the significant accomplishment made by the users of the synchrotrons (there were about 6500 users of the 4 facilities in 2001), coordination of workshops and user meetings, budget issues and others. It was felt that the meeting served a very useful purpose and the group agreed to meet periodically and keep in regular email contact when more timely action was needed. A next possible meeting date will be around the summer BESAC meeting.

Discussions continued Thursday, when Murray Gibson and Steven Dierker visited SSRL for presentations on SSRL activities and a tour of the facility. Also occurring this week was the annual coordination meeting between SSRL and ALS, this time held at the ALS. These meetings, which include the managers of the two facilities, are aimed at strenghtening the cooperation and coordination between the two laboratories in many areas, including research and development, meetings and workshops, and shutdown schedules.

3.  Highlights of the Workshop on Recent Advances in the Medical Applications
      of Synchrotron Radiation

      (contacts: Ed Rubenstein, exr@stanford.edu,
                     Amy Rutherford, amyr@ssrl.slac.stanford.edu)

Scientists from ALS, APS, Ben-Gurion, BNL, Elletra, ESRF, HASYLAB, KEK, LLNL, NSLS, SPring-8, SSRL, the Stanford Medical Center, the UCSF Medical Center and the University of Oregon met at SLAC on March 4-5 to discuss the results of their current research on medical uses of synchrotron radiation.

A number of themes emerged. First, it is apparent that as medicine is becoming molecular, researchers in this discipline are focusing on ever more detailed use of information to understand disease and design drugs to intervene. The initial medical use of synchrotron radiation in coronary angiography studies continues to evolve and the images have reached exceedingly high quality. Capillary perfusion of the myocardium is now being quantified. Striking images of the interior of the ossicles were presented, and new approaches to the study of pulmonary airways, the lung parenchyma, the cerebral vasculature and the choroid plexus were discussed. Novel approaches have resulted in substantial improvements in breast imaging.

Many of the advances are the result of new optical systems based on phase contrast, x-ray interferometry, and diffraction enhanced imaging. The latter method is under development in a number of laboratories. Novel dark field images were presented as well. Advances are also being made in radiotherapy using microbeams and Auger electrons.

Several papers discussed the forthcoming development of compact storage rings dedicated to medical use. Just as storage rings have passed through several generations, two generations of investigators in this field were represented at the meeting. Former trainees are now international leaders. This was the first international workshop on medical uses of synchrotron radiation to be held at SSRL, where the field was born, nearly 23 years ago.

(see also: workshop program and abstracts)

4.  SPEAR3 Update
      (contact: Cathy Knotts, knotts@ssrl.slac.stanford.edu)

In order to minimize the shutdown period for SPEAR3 installation and commissioning (April 2003-January 2004), much of the preparatory work has already been performed or will be scheduled shortly. Although most of this work is behind the scenes, there will be times when this work impacts specific beam lines and the users who want to utilize those beam lines. A summary of recent and upcoming beam line upgrade activities was recently sent to users by email and is also posted on our SPEAR3-Update page.

After the SPEAR3 installation, most of the beam lines will benefit from optics improvements but relatively modest conceptual changes. Some exceptions to this, based on current plans and resources, may include the following:

  • BL3-3 will be optimized for 1750-5000 eV operations.

  • BL4 and BL7 will benefit from new insertion devices (20-pole, 2.1-T wigglers) to fully utilize the SPEAR3 source characteristics and provide new capabilities.

  • BL4-3 and BL7-3 will obtain collimating mirror optics.

  • BL7-2 will have the conventional toroidal mirror focusing system replaced with a cylindrical mirror and a sagittal focusing monochromator for improved high energy performance.

  • BL8-2 will be optimized for 250-1900 eV operations with the inclusion of a multilayer grating and reconfigured mirror optics.

All of these activities are resource driven, so these plans could be accelerated or delayed depending on the availability of funding. With that caveat, one of the most important goals of the beam line development group is to have all front ends 500 mA compatible when SPEAR3 turns on. Front ends include isolation valves and all other components related to isolating radiation and vacuum from the SPEAR storage ring. Another goal is to have the insertion device beam lines 500 mA compatible as quickly as possible; consequently, BL5, BL6, BL9, BL10, and BL11 are scheduled to be ready in January 2004, when user commissioning and operations are expected to resume. We anticipate that BL7 will be 500 mA compatible around June 2004. BL4 will still require extensive work and resources, so this beam line may not be 500 mA compatible until 2006 (unless additional funding is obtained in the relatively near future). In the interim, we plan to accommodate the small angle scattering users on BL6-2. Bending magnet beam lines (BL1, BL2, BL3, and BL8) will require additional work to be fully compatible with SPEAR3. SSRL is currently pursuing technical options that will allow us to operate these beam lines prior to their SPEAR3 upgrade. We look forward with excitement to the new scientific opportunities/capabilities provided by SPEAR3, and we appreciate the continued cooperation of users to cope with the challenges of this transition. We will strive to keep users informed of the SPEAR3 upgrade activities, and we encourage users with specific questions to contact user research administration or the scientific or technical support staff assigned to the respective beam lines.

5.  Upcoming Events at SSRL and Elsewhere

6.   User Research Administration Announcements
       (contacts: Cathy Knotts, knotts@ssrl.slac.stanford.edu,
                        Lisa Dunn, lisa@ssrl.slac.stanford.edu)

  • The X-ray and VUV beam time assignments for the final scheduling period in 2002 (May 1-July 8) have been distributed to spokespersons and the schedule has been updated on the website.

  • All SSRL proposals that will lose beam time during the SPEAR3 shutdown (April 2003-January 2004) have been granted an additional one-year extension. Also due to SPEAR3, new X-ray/VUV proposals will only be accepted once this year; the deadline is May 1, 2002. (see: Proposal Submittal and Scheduling Procedures for Research at SSRL)

  • Spokespersons with proposals eligible to receive beam time on macromolecular crystallography beam lines during the June 1-July 8, 2002 scheduling period will receive an email communication in early April inviting them to request time by April 19. The link to the Beam Time Request form will be included in that message and is also available at the SMB website.

SSRL Headlines is published electronically monthly to inform SSRL users, sponsors and other interested people about happenings at SSRL. SSRL is a national synchrotron user facility operated by Stanford University for the U.S. Department of Energy Office of Basic Energy Sciences. Additional support for the structural biology program is provided by the DOE Office of Biological and Environmental Research, the NIH National Center for Research Resources and the NIH Institute for General Medical Sciences. Additional information about SSRL and its operation and schedules is available from the SSRL WWW site: http://www-ssrl.slac.stanford.edu/

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Last Updated: 22 APR 2002
Content Owner: L. Dunn
Page Editor: L. Dunn