ALSNews Vol. 278

First proof of ferromagnetic carbon

Contact: Hendrik Ohldag, HOhldag@stanford.edu

Although it has long been suspected that carbon belongs on the short list of materials that can be magnetic at room temperature, attempts to prove that pure carbon can be magnetized have remained unconvincing. However, using a proton beam and an advanced x-ray microscope at the Advanced Light Source, a multinational team of researchers from the Stanford Synchrotron Radiation Laboratory, the University of Leipzig, and the ALS finally put to rest doubts about the existence of magnetic carbon. Read more…

Publication about this research: H. Ohldag, T. Tyliszczak, R. Höhne, D. Spemann, P. Esquinazi, M. Ungureanu, and T. Butz, “π-electron ferromagnetism in metal-free carbon probed by soft x-ray dichroism,” Phys. Rev. Lett. 98, 187204 (2007).

Symmetry breaking of H₂ dissociation by a single photon

Contact: Thorsten Weber, TWeber@lbl.gov

A single hydrogen (or deuterium) molecule consists of only two protons (deuterons) and two electrons and is perfectly symmetric. Linearly polarized photons are similarly symmetric. So one might think that the angular distribution of photoelectrons resulting from photoionization of the molecule by the photon accompanied by dissociation into a hydrogen atom and a hydrogen ion would itself be symmetric. However, an international team of researchers from Germany, Spain, and the U.S. has now shown that this need not be the case. When there are multiple quantum paths for the process, interference between waves in the coherent superposition of electron states (which exists when the molecular fragments are still close together) skews the distribution by breaking the molecular symmetry. Read more…

Publication about this research: F. Martín, J. Fernández, T. Havermeier, L. Foucar, Th. Weber, K. Kreidi, M. Schöffler, L. Schmidt, T. Jahnke, O. Jagutzki, A. Czasch, E.P. Benis, T. Osipov, A.L. Landers, A. Belkacem, M.H. Prior, H. Schmidt-Böcking, C.L. Cocke, and R. Dörner, “Single photon–induced symmetry breaking of H₂ dissociation,” Science 315, 629 (2007).

Structure and receptor specificity of an avian flu antigen

Contacts: Ian Wilson, wilson@scripps.edu; James Stevens, JStevens@scripps.edu

To date, the H5N1 avian influenza viruses, which are currently circulating in domestic and wild birds on three continents, have only a limited ability to infect humans. However, with continued outbreaks of the virus in poultry and wild birds, the potential for the emergence of a human-adapted H5 virus, either by reassortment (the mixing of genetic material from similar viruses) or mutation, is seen as a major threat to public health worldwide. Of the three influenza pandemics of the last century, the 1957 (H2N2) and 1968 (H3N2) pandemics involved avian-human reassortments. The origin of the 1918 influenza virus (H1N1), which killed about 50 million people worldwide, is unknown. Although a number of viral factors can determine the host range restriction and pathogenicity of influenza A viruses, recent evidence suggests that hemagglutinin (HA), the principal antigen on the viral surface, is a critical factor for efficient human-to-human transmission. Researchers have now solved the HA structure to 2.9 Å at the ALS and analyzed its specificity to human receptors. Read more…

Publication about this research: J. Stevens, O. Blixt, T.M. Tumpey, J.K. Taubenberger, J.C. Paulson, and I.A. Wilson, “Structure and receptor specificity of the hemagglutinin from an H5N1 influenza virus,” Science 312, 404 (2006).

Material Management group keeps the ALS on track

Contact: Gary Giangrasso, GJGiangrasso@lbl.gov

Need to ship something, store something, move something, set something up? The Material Management group will do it. Gary Giangrasso (section manager), Todd Anderson, Derrick Crofoot, and Jason De Ponte are located in the warehouse adjacent to the ALS (Building 7). The group wears two “hats”—it is responsible for both material and property management for the ALS Division. In its material management capacity, the group provides shipping, receiving, gas-bottle ordering, refilling and servicing of liquid nitrogen dewars, temporary storage, endstation setup services, and movement/assembly of office and lab equipment. Giangrasso and his team maintain a stockroom of parts and equipment in the warehouse (including safety devices) commonly needed by ALS users and technicians. Stockroom supplies are accessible by key card 24 hours a day. Another service provided is the generation of purchase requisitions for ALS staff and users requesting new supplies and equipment. Also, a new barcode system has been implemented for tracking chemicals that arrive at the ALS on a daily basis.

Todd Anderson, Jason De Ponte, Derrick Crofoot, and Gary Giangrasso.

In its property management capacity, the group handles property issues and questions about custodian and location changes for DOE assets out of the property management office (Bldg. 7, Rm. 102B). They also generate property passes for laptop computers and equipment that will be taken off site for business travel or home use.

2007 ALS Users’ Meeting approaches

The ALS Users’ Meeting will be held on site at Berkeley Lab—from Thursday, October 4, to Saturday, October 6—and will offer a variety of invited talks, workshops, and selected science highlights. For the first time, this year’s meeting will feature a joint plenary session with the Molecular Foundry Users’ Meeting, which is taking place simultaneously at Berkeley Lab. In addition, we will hold a joint poster session and dinner to bring the two user communities together around their research. More information on the Users’ Meeting is available on the Users’ Meeting Web site. Furthermore, there will be twelve workshops this year, three to be held in conjunction with the Foundry.

The workshops’ abstract deadline is now upon us. Workshop organizers requiring additional information should contact alsum@lbl.gov, or the meeting chairs Peter Fischer (PJFischer@lbl.gov) and Ken Goldberg (KAGoldberg@lbl.gov).