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SSRL Headlines Vol. 10, No. 1  July, 2009


Contents of this Issue:

  1. SSRL Initiates 200-mA Beam Line Operations
  2. Science Highlight — Molecular Mixing in Organic Solar Cells
  3. Science Highlight — Understanding Nature's Assembly of Molecules to Improve Tomorrow's Electronics
  4. New BL5 Branch Line Funded by DOE
  5. X-ray/VUV Beam Time Requests Due August 1
  6. Register to Participate in the SSRL/LCLS Users' Conference - October 18-21, 2009
  7. Submit Nominations for Spicer, Klein and Lytle Awards
  8. Call for User Science Posters and Outstanding Student Poster Competition
  9. SSRL Structural Molecular Biology Summer School - September 8-11, 2009
  10. Vandalism at SSRL
  11. Provide Feedback Using User Portal

1.   SSRL Initiates 200-mA Beam Line Operations
       (contact: T. Rabedeau,

Users arriving at SSRL on Wednesday, July 29, found beam lines operating at 200 mA, or twice the previously normal operating current, with a concomitant two-fold increase in photon flux and brightness. This development, coupled with the recent initiation of top-off operations, represent major milestones in realizing the full potential of the SPEAR3 source. These two milestones are the tangible manifestations of the efforts of a large group of SSRL staff working in collaboration with the SLAC Radiation Protection Department and the DOE Site Office. In particular, each of these developments followed extensive careful studies and reviews of the radiation safety aspects of these performance envelope enhancements as well as field commissioning studies of the operating systems. The last of these radiological commissioning studies was completed successfully Tuesday evening about 12 hours before delivering the first 200-mA beam to users.

SSRL will operate at 200 mA for the remainder of the FY09 run which will provide staff and users alike the opportunity to assess the performance of the beam line optics under the increased power loading of 200 mA operations as well as detector and experimental instrumentation performance with the two-fold higher brightness and flux. During the scheduled summer shutdown a new beam line beam containment system will be installed on each beam line and the beam lines reviewed for full 500-mA operations. Following the summer down, SPEAR3 will continue to deliver 200 mA beam in the fall, while conducting 500-mA radiological commissioning activities during selected accelerator physics shifts. Successful completion of this program is anticipated by January, resulting in authorization of greater than 200-mA user operations. Concurrent with this effort, some accelerator physics shifts will be devoted to understanding the impact of frequent fills (i.e., possibly as frequent as every ten minutes) on data quality. Based on this experience in early 2010, SSRL will raise the SPEAR3 current and injection frequency in a systematic program designed to increase the SSRL brightness and flux while preserving stored current and photon beam stability, user data quality, and facility safety.

2.  Science Highlight — Molecular Mixing in Organic Solar Cells
       (contact: M.F. Toney,

highlight figure
Solar panels contain a number of solar cells that convert light into electricity. Solar cells are traditionally made of crystalline silicon, which presently have 15-20% efficiency in conversion of light into electricity. However, these traditional cells are bulky and have high production costs that can take 5-7 years of solar panel operation to recover. Using solar cells made from organic materials could lower their production costs. This would lessen the time it takes for solar panels to generate more energy than consumed during production and would also result in more widespread application of solar energy.

The most common organic solar cell implementation has a polymer/fullerene bulk-heterojunction (BHJ) blend as the active (sunlight absorbing) layer. To form the BHJ, the polymer and fullerene (a buckyball) are blended and typically spontaneously self-assemble into the BHJ. It has remained a puzzle, however, why some polymerfullerene systems reach optimal efficiency at equal parts polymer and fullerene and other systems optimize at around 80% fullerene content.

To understand what causes this variation in efficiencies depending on the polymer molecule, scientists from SLAC and Stanford used Beam Lines 11-3, 2-1, and 7-2 for x-ray diffraction experiments to explore the materials at a molecular scale. They found that for some polymers the fullerene molecules intercalated (or co-crystallized) within the crystalline structure of the polymer provided there was enough space within the polymer. This was surprising, since the researchers were expecting to find two separate materials: the pure polymer and pure fullerene. The researchers found only the intercalated phase for BHJs made with equal parts polymer and fullerene. However, when the polymer:fullerene ratio was 1:4, two phases did form; one was the polymer-fullerene co-crystal and the other was pure fullerene. These results fully explain the dependence of efficiency on polymer:fullerene blend ratio.

This study is the first to find fullerene molecules intercalated within a polymer crystal. How this co-crystallization affects efficiency and whether it is a desirable trait remains to be seen. This and future knowledge gained from analyzing the structure of these materials will allow researchers to understand the reasons for the diverse behavior of different materials and to design more efficient materials. This work was published in the journal Advanced Functional Materials.

To learn more about this research see the full scientific highlight.

3.  Science Highlight — Understanding Nature's Assembly of Molecules to Improve Tomorrow's Electronics
       (contacts: S.C.B. Mannsfield,; M.F. Toney,

highlight figure
Nothing seems to move as fast as the field of consumer electronics. A browse through a technology store reveals the dizzying array of space-age -seeming products like flat screen TVs, touch screen phones, and mp3 players. A new development in electronics is on the horizon, one that may bring us roll-up flat screens and high-definition display clothing. These will be made possible using the thin and energy efficient organic light emitting diodes (OLEDs), which are based on organic semiconductor technology. Both a desire for less expensive, more convenient technologies and a concern for energy conservation have heightened interest in the field of organic semiconductors.

Organic semiconductors have the properties of silicon-based semiconductors, found ubiquitously in the diodes, transistors, and chips that run our modern, computerized devises, but they are made from organic materials. They have the potential to be far less expensive to make than the classic silicon versions and can be made flexible and lighter weight over large areas. One of the most popular type of organic semiconductor is made from thin films of pentacene, a long, polycyclic aromatic hydrocarbon molecule. In this form, electrical current flows primarily through the first few layers of the pentacene material.

A research group led by Zhenan Bao of Stanford University collaborating with SSRL scientists Stefan Mannsfeld and Michael Toney has used Beam Line 11-3 to investigate the structure and properties of single molecular layers of pentacene. Using grazing incidence X-ray diffraction (GIXD) and newly developed modeling tools, they determined for the first time the precise structural arrangement and the orientation of the molecules from the weakly-diffracting films.

The researchers discovered that the molecules stand upright on the substrate plane. Looking down at the plane, the molecules pack in a herringbone pattern. They calculated that this orientation of pentacene leads to the material's electronic properties, which exceed those of single crystalline pentacene. This research demonstrates that determination of the structural properties of a single layer of organic semiconductor molecules is possible and that this information can yield valuable insight into the function of these molecules. This work was published in the March issue of the journal Advanced Materials.

To learn more about this research see the full scientific highlight.

4.  New BL5 Branch Line Funded by DOE
       (contacts: D. Lu,; Z.-X. Shen,

The Department of Energy has awarded $4.8 million in Single Individual and Small Group Research (SISGR) grants to the Stanford Institute for Materials and Energy Science (SIMES) and the Stanford Synchrotron Radiation Lightsource (SSRL) for building a new photoemission branch line at SSRL. This new branch line will be located at current Beam Line 5 next to the existing branch line 5-4. Featuring an elliptically polarized undulator (EPU) and a plane grating monochromator (PGM), this new branch line will complement the normal incidence monochromator (NIM) branch line with extended photon energy range (up to 150 eV) and full polarization control. Such a combination of NIM and PGM branch lines will allow the optimization of each branch line for different type of experiments. While the NIM branch line is optimized for ultrahigh resolution ARPES experiments in relatively low photon energy, the PGM branch-line will be optimized for high photon flux, wider photon energy range with added capability of performing spin-resolved photoemission studies. Users will have the flexibility in choosing either branch lines for their scheduled beamtime. It will take approximately three years to complete the beam line construction work and the commissioning of the new branch line is expected to start in late 2012.

For information on other photon science-related projects funded under the SISGR grant program see 7/27/2009 SLAC Today article

5.   X-ray/VUV Beam Time Requests Due August 1
       (contact: C. Knotts,

The current run year ends and we shut down for maintenance/upgrades on Monday, August 10 at 6 am. The next run will begin in late October, and the 2009-10 SPEAR operating schedule, which includes information on scheduled maintenance and accelerator physics studies, is available on the SSRL website.

If you are interested in requesting beam time on X-ray/VUV beam lines for the first scheduling period for the 2010 run (~late October through early February 2010), submit your request(s) before August 1; submit Macromolecular Crystallography requests by September 15.

Submit beam time requests by logging into the SSRL User Portal at:

Enter your email address and your password or click on 'request a password'. We have tried to make the process to submit requests easier by adding a feature that allows you to clone (copy) a previous request. With the new system, you also have the ability to save a draft so that you can edit, complete or delete it at a later date - as long as it is completed by the deadline. Remember to submit a SEPARATE request for each proposal, beam line, equipment configuration and/or each individual beam time period requested. If you select a beam line that has multiple crystal options, you will be prompted to indicate the crystal you need for your first and second choice beam line(s). If the availability you indicate on your beam time request changes, please let us know immediately.

6.   Register to Participate in the Annual SSRL/LCLS Users' Conference - October 18-21, 2009
       (contact: C. Knotts,
User Mtg banner

Register today to participate in the Annual LCLS/SSRL Users' Meeting and Workshops, October 18-21, 2009. The annual conference is a great opportunity to learn about the latest plans, new developments, and user research as well as to interact with other scientists, potential colleagues, and vendors of light source related products and services.

The event kicks off on October 18 with a special symposium celebrating 35 years of outstanding science at the Stanford Synchrotron Radiation Lightsource. In addition to reviewing technical accomplishments and research highlights, future scientific and technical opportunities for SSRL will be discussed.

LCLS/SSRL 2009 officially begins on October 19 with a joint plenary session featuring updates from SLAC and DOE, a preview of the workshops, a user science poster session, and a keynote presentation. The Spicer Young Investigator Award, Klein Professional Development Award, Lytle Award, and the Outstanding Student Poster Session Awards will be presented on this day. Submit abstracts for the user poster session by September 5 at:

On October 20, separate concurrent sessions will focus on SSRL and LCLS facility development, instrumentation, and user science, followed by meetings of the respective SSRL and LCLS Users' Organizations.

On October 21, several concurrent workshops will be held including Microimaging; Nanoscale Imaging with the SSRL STXM; Macromolecular Crystallography; Soft X-ray Beam Line Experiment Preparation; and X-ray Pump Probe Experiment Preparation.

7.   Submit Nominations for Spicer, Klein and Lytle Awards
       (contact: C. Knotts,

Please take a few moments to consider nominating your colleagues or students for one or more of the following awards which will be presented at the Joint SSRL and LCLS Users' Meeting, October 18-21, 2009:

William E. and Diane M. Spicer Young Investigator Award —due August 1

Melvin P. Klein Professional Development Award —due August 1

Farrel W. Lytle Award —due August 15

8.   Call for User Science Posters and Outstanding Student Poster Competition
       (contact: C. Knotts,

We invite you to share your research during the Poster Session (October 19) of the Annual Users' Meeting. Students, in particular, are encouraged to present posters and compete for prizes, which include a certificate and a $100 award. Representatives of the SSRL Users' Organization will judge student posters during the poster session, and prizes for outstanding posters will be presented during the meeting. In addition to the reduced student registration fee, students presenting posters also receive a free dinner - just sign up and indicate this when you register, see instructions at:

Register at:

Submit abstracts for the user poster session by September 5 at:

9.   SSRL Structural Molecular Biology Summer School - September 8-11, 2009
       (contact: R. Sarangi,

Download Poster
The biennial SSRL Structural Molecular Biology (SMB) Summer School provides a lecture series and practical application workshops on biological scientific applications of synchrotron radiation. The goal of the school is to disseminate information about the scientific opportunities in synchrotron radiation applications and train participants on the theoretical aspects, data acquisition and practical data analysis of different experimental techniques.

The 2009 SMB Summer School will focus on the use and application of X-ray Absorption Spectroscopy, Macromolecular Crystallography and Small Angle X-ray Scattering. Invited lectures from experts in these fields will be at the graduate student/post-doctoral level, but will also be appropriate for experienced researchers with expertise in one technique and an interest in learning other techniques to further the scope of their research. The four-day summer school will feature two days of lectures covering theoretical and experimental aspects, and two days of hands on training in data analysis. The afternoon of the last day will be reserved for question-and-answer sessions hosted by the co-chairs, which will be aimed at addressing specific queries from the participants.

Co-chairs for the 2009 SMB Summer School are SSRL Staff Scientists Ritimukta Sarangi (, Clyde Smith ( and Thomas Weiss ( Funding for the SMB Summer School program is provided by NIH-NCRR and DOE-BER.

Apply at:

10.   Vandalism at SSRL

As you may be aware from accounts of the incident in the news media, a very serious act of vandalism was committed on BL1-5 at SSRL over the weekend of July 17-19. During this isolated event, a large number of samples belonging to the Joint Center for Structural Genomics were intentionally removed from their storage dewars and thus destroyed.

SLAC management took this action very seriously resulting in a rapid response by authorities. As a result of this vigorous investigation, SLAC Director Persis Drell announced to staff earlier this week that Federal authorities had made an arrest in the case and the suspect taken into custody. She expressed her thanks to the DOE Inspector General, DOE Site Office, FBI, San Mateo County Sheriff's Office, Stanford University Department of Public Safety and SLAC Security for their thorough investigation and for bringing this case to a rapid conclusion.

See also: Persis Drell's 7/31/09 SLAC Today communication discouraging tailgating through security gates at:

11.   Provide Feedback Using User Portal
       (contact: C. Knotts,

Use the new User Portal to view your allocated beam time and submit an End of Run Summary after each scheduled experiment. Comments on your experience at SSRL are extremely important to us as we strive to provide outstanding customer service on a continuing basis. In addition, your input allows us to meet our mission requirements, including assessment and reporting. Thank you for your feedback.


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.


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Last Updated: 30 July 2009
Content Owner: L. Dunn
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