No. IV/11 - 22 December 2011
PSI photon, neutron and muon user facilities newsletter
This year we have celebrated the tenth anniversary of the Swiss Light Source. User operation started in 2001 with just four beamlines. Now the SLS has eighteen beamlines, covering the entire radiation spectrum from the infrared to the hard X-ray range. From day one of its operation, the SLS storage ring featured small-gap in-vacuum undulators in combination with top-up injection. These features, combined with stable temperature in the ring tunnel and sophisticated beam position monitoring, provided extremely high stability and reliability. Recently, the machine group achieved a 'world record' low value for the vertical emittance of 1pm rad.
The users have greatly profited from these excellent beam conditions. In the first ten years of SLS operation, the SLS users have generated more than 2000 publications, many of them in high-impact journals. The in-house staff has contributed substantially to the advancement of high-resolution spectroscopy, imaging and diffraction. Last but not least, our detector group is a world leader in the development of hybrid pixel detectors (PILATUS). In the years to come PSI needs to put many of its resources into the realization of its X-ray free electron laser SwissFEL and both SLS staff and the machine physics department are heavily involved in the project. As a consequence of this engagement, the SLS will certainly enter a consolidation phase. However, maintenance and regular upgrades of the SLS and its beamlines will remain a priority over the next ten years.
I would like to thank all users for the excellent science that they have brought to the SLS and the PSI staff for their inventiveness and support.
J. Friso van der Veen
SLS - Life sciences
New insights into the cell's protein factoryS. Klinge et al, Science 334, 6058 (2011)
Eukaryotic ribosomes are among the most complex cellular machineries of the cell. These large macromolecular assemblies are responsible for the production of all proteins and are thus of pivotal importance to all forms of life. Two independent research groups at the ETH Zürich and the Institute of Genetics and Molecular and Cellular Biology in Strasbourg have obtained new insights into the atomic structure of the eukaryotic ribosome. The results have been published in the journal Science. All diffraction data were measured with synchrotron light at the Swiss Light Source macromolecular crystallography beamline X06SA at the Paul Scherrer Institute.
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SINQ - Plants, water and soil
Three-dimensional visualization and quantification of water content in the rhizosphereA.B. Moradi et al, New Phytologist 192, 653 (2011)
An international research team has demonstrated by experiments at SINQ that the soil in the vicinity of roots contains more water – contrary to the earlier belief that there must be less water in this region, as the plant takes up water from the soil. Apparently, however, plants create a small water reserve that helps to tide them over through short periods of drought. These findings could help, in the long term, in the breeding of plants to cope better during periods of drought or in support of the development of efficient irrigation systems. These results were obtained from experiments carried out with the benefit of neutron tomography at the Paul Scherrer Institute, using a method that makes it possible to exactly show the distribution of water to a fraction of a millimetre, without having to remove a plant from the soil.
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SμS - Matter under extreme conditions
Muon spin rotation investigation of the pressure effect on the magnetic penetration depth in YBa2Cu3OxA. Maisuradze et al, Physical Review B 84, 184523 (2011)
The pressure dependence of the magnetic penetration depth λ in polycrystalline samples of YBa2Cu3Ox with different oxygen concentrations x=6.45, 6.6, 6.8, and 6.98 was studied by muon spin rotation (μSR). The pressure dependence of the superfluid density ρs∝1/λ2 as a function of the superconducting transition temperature Tc is found to deviate from the usual Uemura line. The ratio (∂Tc/∂P)/(∂ρs/∂P) is smaller by a factor of ≃2 than that of the Uemura relation. In underdoped samples, the zero-temperature superconducting gap Δ0 and the BCS ratio Δ0/kBTc both increase with increasing external hydrostatic pressure, implying an increase of the coupling strength with pressure. The relation between the pressure effect and the oxygen isotope effect on λ is also discussed. In order to analyze reliably the μSR spectra of samples with strong magnetic moments in a pressure cell, a special model was developed and applied.
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SwissFEL - News
Recent SwissFEL workshops 2011
On September 12 and November 21, 2011, two Workshops were held at the University of Bern with the goal of collecting user input for the design of the initial set of instruments at the SwissFEL hard X-ray „ARAMIS“ undulator beamline. The first Workshop concentrated on spectroscopic experiments and was attended by 40 scientists from 10 different institutions, and the second Workshop focused on scattering and diffraction experiments and was attended by 80 scientists from 20 institutions. The results of the Workshops, a booklet of 35 project posters (see cover picture to the left), a discussion summary of requested capabilities and features and a preliminary definition of 4 experimental user groups, are posted here. The next step in the instrument design process will be four focused Workshops, to be held at PSI – for topics and dates, please consult the SwissFEL web page.
New calls for proposalsSLS: PX-beamlines
deadline: February 15, 2012
deadline: March 15, 2012
deadline: May 15, 2012
SµS/instruments GPS, LTF, and GPD
deadline: June 2012
Joint neutron and muon powder diffraction proposals
deadline: February 15, 2012
An overview about all proposal submission deadlines of the PSI facilities can be obtained here.
Upcoming eventsJanuary 25-26: SμS Users' Meeting 2012, PSI Villigen, CH, more information
January 25-27: European XFEL Users' Meeting, Hamburg, DE, more information
January 29 - February 1: Neutrons and Food 2012, Delft, NL, more information
January 29 - February 3: 5th European School on Multiferroics, Monte Verita, CH, more information
Facility newsSLS: 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 saw first synchrotron light in December. Commissioning of the optics, and installation of the end station are planned for 2012.
SINQ: EIGER ready for neutrons
The construction of the thermal triple-axis spectrometer EIGER has now been finished. EIGER is a new modern instrument with a double focusing monochromator and an efficient non-magnetic shielding in order to allow experiments with strong magnetic fields. Tests with neutrons will be made after the shutdown in spring 2012 and we expect that EIGER will be ready for first experiments in summer.
SINQ: New proposal record
In 2011 more than 400 new SINQ proposals have been submitted, which is a new all time record for the facility. The proposals, which have been submitted in November 2011 are presently under evaluation. The results will be published in early February.
SμS: Successful user operation 2011
A total of 226 experiments were performed on the SμS instruments in 2011 by 160 different users. The facility received 196 new proposals - a number that is remarkably high, since no call was opened for DOLLY and ALC and proposals could be submitted for four instruments only. So far the largest proposal number was received in 2010 with 201 proposals for six instruments!