Resumption of full scientific operation at BESSY II delayed
the 7-Tesla Multipole Wiggler: after one year working on it, the wiggler came back from Novosibirsk as planned but had to be removed from the storage ring again. The reason for highly elevated operating temperatures are investigated.
While the lengthy summer shutdown with its comprehensive updating and maintenance work has been completed as planned, there have been some unforeseeable disruptions that will delay the resumption of regular Top-Up operations at present. The scientific operating time for users which was unavailable in October will be made up at the beginning of 2014.
Initial operation of the storage ring has been successfully commenced; however the electron source of the Linac has displayed unexpected arcing voltages. Storage ring injection has therefore been transferred from the Linac over to the Microtron. The repair work is progressing with the goal of being able to use the Linac again as soon as possible.
As long as injection is being carried out with the help of the Microtron, comprehensive operation in Top-Up mode is not possible, unfortunately, while insertion of the usual individual pulses into the gaps of multi-pulses in hybrid mode is not available.
Due to the problems with the Linac, no external scientific work could take place during the second week of October. The down-time will made up through an additional operating week at the beginning of 2014.
External scientific work with BESSY II resumed on 15 October: during the day, the storage ring will only be operated in restricted decay mode, however, while at night in reduced Top-Up mode. This assures that scientific use is available for the majority of BESSY II users.
Moreover, the 7-Tesla Multipole Wiggler, which supplies the EDDI, MAGS, and ASAXS beamlines with hard X-ray radiation, displayed highly elevated operating temperatures and had to be removed from the storage ring again. Repairs are in progress, though the Wiggler will probably only be able to come online again in December, however.
This means that external scientific work with the three beamlines mentioned above cannot take place probably until the end of the year.
All members of the BESSY II team keenly regret these unforeseen restrictions to our users as well as our own in-house colleagues. They request your understanding and are working hard to restore comprehensive external operation again as quickly as possible.
Current information about operational status of BESSY II can be viewed on the informational systems of BESSY II in the internet at http://infosystem.bessy.de/
- BESSY II: How intrinsic oxygen shortens the lifespan of solid-state batteriesAlthough solid-state batteries (SSBs) demonstrate high performance and are intrinsically safe, their capacity currently declines rapidly. A team from the TU Wien, Humboldt-University Berlin and HZB has now analysed a TiS₂|Li₃YCl₆ solid-state half-cell in operando at BESSY II using a special sample environment that allows for non-destructive investigation under real operating conditions. Data obtained by combination of soft and hard X-ray photoelectron spectroscopy (XPS and HAXPES) revealed a new degradation mechanism that had not previously been identified in solid-state batteries. They have gained some surprising insights, particularly regarding the harmful role played by intrinsic oxygen. This study provides valuable information for improving design and handling of such batteries.
- Spintronics at BESSY II: Real-time analysis of magnetic bilayer systemsSpintronic devices enable data processing with significantly lower energy consumption. They are based on the interaction between ferromagnetic and antiferromagnetic layers. Now, a team from Freie Universität Berlin, HZB and Uppsala University has succeeded in tracking, for each layer separately, how the magnetic order changes after a short laser pulse has excited the system. They were also able to identify the main cause of the loss of antiferromagnetic order in the oxide layer: the excitation is transported from the hot electrons in the ferromagnetic metal to the spins in the antiferromagnet.
- Environmental Chemistry at BESSY II: Radicals in waterwaysHow do radicals form in aqueous solutions when exposed to UV light? This question is important for health research and environmental protection, for example with regard to the overfertilisation of water bodies by intensive agriculture. A team at BESSY II has now developed a new method of investigating hydroxyl radicals in solution. By using a clever trick, the scientists gained surprising insights into the reaction pathway.