No. I/12 - 30 March 2012

PSI photon, neutron and muon user facilities newsletter

Editorial

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Rafael Abela
Dear Colleagues,


The SwissFEL project is progressing rapidly on three routes: preparation of building permit, design and construction of prototypes for the accelerator and the challenging phase of preparing future experiments. The final decision for the project will be taken by the Swiss parliament in fall of this year. Academic groups from Swiss universities and PSI are performing experiments at the XFEL facility LCLS (USA), testing new devices and measuring strategies at the SLS and planning tests at SACLA (Japan). All this exchange of experiences will strongly influence the specific future user-stations of SwissFEL. Furthermore, the interaction with future users has been strengthened: two scientific workshops on hard X-Ray instrumentation have been held in the fall of 2011. The first workshop focused on spectroscopic experiments, while the second one was dedicated to scattering and diffraction experiments. The results of the workshops are still available on the web. The next steps in the design process will be discussed in the course of five topical meetings, to be held at PSI until summer of 2012.

Two collaboration agreements with European institutions were signed in November 2011. A “Swiss-Swedish Partnership” on Accelerator, Photon and Neutron Science, between PSI, EPFL, the Royal Institut of Technology in Stockholm, the University of Uppsala and the University of Stockholm covers technology developments for the next generation of free-electron lasers as well as collaborations in photon and neutron science. The second partnership, a MoU between PSI and STFC (UK), will enable the exploitation and expansion of technological and scientific capabilities of the future SwissFEL.


Rafael Abela on behalf of the PSI SwissFEL team

Research highlights

SLS - Materials Sciences

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Creating magnetism takes much longer than destroying it

S.O. Mariager, Physical Review Letters 108, 087201 (2012)
Researchers at the Paul Scherrer Institute are finding out how long it takes to establish magnetism and how this happens. Establishing a magnetically ordered phase in the metallic alloy iron-rhodium takes much longer than the reverse process of demagnetization. This fact was established by researchers of the Paul Scherrer Institute (PSI), Switzerland, together with colleagues of an international collaboration. Magnetism is established in a two-step process. Initially, small magnetic regions form, but have random orientation. Subsequently, these regions rotate until they all have a common orientation. This is reported in an article which has recently been published in the renowned journal “Physical Review Letters”. The result comes from basic research, but has relevance for the computer industry, as it shows which processes limit the speed of magnetic data storage and where improvements might be made.
Read the full story



SINQ - Functional materials

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Coupling of Magnetic and Ferroelectric Hysteresis by a Multicomponent Magnetic Structure in Mn2GeO4

J.S. White et al, Physical Review Letters 108, 077204 (2012)
The olivine compound Mn2GeO4 is shown to feature both a ferroelectric polarization and a ferromagnetic magnetization that are directly coupled and point along the same direction. We show that a spin spiral generates ferroelectricity, and a canted commensurate order leads to weak ferromagnetism. Symmetry suggests that the direct coupling between the ferromagnetism and ferroelectricity is mediated by Dzyaloshinskii-Moriya interactions that exist only in the ferroelectric phase, controlling both the sense of the spiral rotation and the canting of the commensurate structure. Our study demonstrates how multicomponent magnetic structures found in magnetically frustrated materials like Mn2GeO4 provide a new route towards functional materials that exhibit coupled ferromagnetism and ferroelectricity.
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SμS - Materials Sciences: Coexistence or Separation?

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Superconducting properties of single-crystalline AxFe2-ySe2 (A=Rb, K) studied using muon spin spectroscopy

Z. Shermadini et al, Physical Review B 85, 100501(R) (2012)
We report on the superconducting properties of AxFe2-ySe2 (A=Rb, K) single crystals studied with the muon spin relaxation or rotation (μSR) technique. At low temperatures, close to 90% of the sample volumes exhibit large-moment magnetic order which impedes the investigation of their superconducting properties by μSR. On the other hand, about 10% of the sample volumes remain paramagnetic and clearly show a superconducting response. The temperature dependence of the superconducting carrier density was analyzed within the framework of a single s-wave gap scenario. The zero-temperature values of the in-plane magnetic penetration depths λab(0)=258(2) and 225(2) nm and the superconducting gaps Δ(θ)=7.7(2) and 6.3(2) meV have been determined for A = Rb and K, respectively. The microscopic coexistence and/or phase separation of superconductivity and magnetism is discussed.
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HERCULES School at Swiss Light Source

The annual HERCULES school aims at training young European researchers (PhD students, postdoctoral scientists) in the field of neutron and synchrotron radiation in a broad range of scientific disciplines. The four-week school is organized each year for 70-75 participants and includes practical sessions at large scale user facilities. The 2012 synchrotron radiation practicals took place at Swiss Light Source (SLS, PSI) and at synchrotron SOLEIL in March. During three days the SLS exclusively opened its beam lines for the school and performed practical training on cutting-edge experimental setups, i.e. the same environment setup that is used for research.

New calls for proposals

SLS: PX-beamlines
deadline: June 15, 2012
non-PX beamlines
deadline: September 15, 2012
more information

SINQ/all instruments
deadline: May 15, 2012
more information

SµS/instruments GPS, LTF, and GPD
deadline: June 2012
more information

An overview about all proposal submission deadlines of the PSI facilities can be obtained here.

Upcoming events

April 15-18: NIUS 2012: ESS Neutron Imaging User Symposium, Bad Zurzach, CH, more information

April 19-20: Science and Scientists at ESS, Berlin, DE, more information

April 24: Workshop SwissFEL Experimental Station C: Coherent Diffraction Imaging, PSI, CH, more information

May 7-10: 4th MaMaSELF status meeting, Rigi Kulm, CH, more information

May 22: Workshop SwissFEL 2nd Phase Experimental Stations, PSI, CH, more information

June 4-8: X-FEL school 2012, Annecy, FR, more information

June 19: Workshop SwissFEL Scientific Computing & Data Acquisition, PSI, CH, more information

June 20-22: SGK/SSCr Annual Meeting 2012, Zurich, CH, more information

Facility news

SLS: first light at PEARL
PEARL (Photo-Emission and Atomic Resolution Laboratory) is a new soft X-ray beamline dedicated to surface science. The main synchrotron-based technique is photoelectron diffraction, while scanning tunnelling microscopy provides complementary real-space information. The X-ray optics section of the beamline has been set up, and detected synchrotron light for the first time in December 2011. Commissioning of the optics, and installation of the end station are planned for 2012.
SINQ: conceptual design work for the ESS
Several laboratories at PSI are now involved in the conceptual design of new instruments and in the development of key neutron technologies for the European Spallation Source ESS. The results of these work packages, ranging from the optimization of shielding and moderators to high-intensity reflectometry, will be delivered to the ESS at the end of 2012.
SINQ: sample environment
A new bottom loading closed cycle refrigerator to be used within an Euler Cradle has been commissioned successfully. The CCR reaches 4K and is equipped with a Joule-Thomson stage to extend the accessible temperature range down to 1.6K. Work is in progress to have the devices accessible to users at TRICS in the near future.
SμS: reconstruction of beam line
The major reconstruction of the low energy muon beam line has successfully been completed and tested using low energy protons. It became necessary, because a spin rotator for longitudinal field μSR was implemented. Excellent beam properties like transmission rates and a narrow beam spot have been obtained. Especially advantageous to the former setup is the shortened time of flight between trigger detector and sample, which should result in a better time resolution by a factor of two.

Current Openings

Job opportunities at PSI

Announcements

NMI3-II access programme is back

The next period of the European Union 'Neutron and Muon Integrated Infrastructure Initiative - NMI3-II' has started on February 1, 2012. Again, both SINQ and SμS are NMI3-II partner facilities, which means that eligible users will be able to claim travel and subsistence funds for their experiments at PSI. As before, an explicit application is not necessary since all eligible proposals will enter the selection process. More information about eligibility criteria, selection and funding rules as well as further procedures can be found here.

PSI summer school on condensed matter research 2012

Registration is now open for the 11th PSI summer school on condensed matter physics, which will be organized from August 11-17, 2012 in Zugerberg, Switzerland. The 2012 edition of the traditional school is dedicated to the fascinating and growing field of imaging experiments at large scale facilities. International experts and PSI staff members will introduce and deepen your knowledge of real space imaging from life to materials sciences. Again, the school will be complemented by a hands-on practical training at the PSI large scale facilities for selected participants. More information

FEL Memorandum of Understanding

After a long preparation phase and extensive discussions, a Memorandum of Understanding between all European free-electron laser facilities and accelerator-based short puls facilities is ready to be signed. The MoU is based on the core activities defined during the preparatory phase of the EuroFEL project, (financed by the EU under the acronym IRUVX-PP); the signing ceremony should take place at the spring meeting of the European Association of National Research Facilities (ERF), to be held by the end of May 2012 at DESY.

Imprint
PSI Facility News addresses the users of the PSI large facilities and appears quarterly in English. Any feedback is highly welcome! More information.
Contact: PSI User Office, Phone: +41-56-310-4666, Email: useroffice@psi.ch