muon spin rotation/relaxation; dilution refrigerator; high magnetic fields; unconventional superconductors; quantum magnetism; strongly correlated electrons; magnetic semiconductors; Superconductivity; Magnetism; Muon Spin Rotation/Realaxation; Low Temperatures
Stoykov A, Scheuermann R, Amato A, Bartkowiak M, Konter JA, Rodriguez J, Sedlak K (2011), A lens-coupled scintillation counter in cryogenic environment, in JOURNAL OF INSTRUMENTATION
, 6(2), 1-15.
Sedlak K, Shiroka T, Stoykov A, Scheuermann R (2010), Geant4 Simulation of the New ALC µSR Spectrometer, in IEEE TRANSACTIONS ON NUCLEAR SCIENCE
, 57(4), 2187-2195.
Stoykov A, Scheuermann R, Sedlak K, A time-resolution study with a plastic scintillator read out by a Geiger–mode Avalanche Photodiode, in Nuclear Instruments and Methods A
Stoykov A, Scheuermann R, Sedlak K, Rodriguez J, Amato A, High-Field µSR instrument at PSI: detector solutions, in Physics Procedia
Sedlak K, Scheuermann R, Shiroka T, Stoykov A, Raselli R A, Amato A, MusrSim and MusrSimAna — Simulation Tools for µSR Instruments, in Physics Procedia
We propose the purchase of a custom designed dilution refrigerator for the new high field muSR instrument. This novel instrument will be located at the Swiss Muon Source at the Paul Scherrer Institute. Similar to all the other instruments of our facility it is open, free of charge, to scientific visitors from Switzerland and abroad, who have submitted a proposal and obtained approval from the user committee.Extensive cryogenic know-how is available at PSI. This will ensure that the dilution refrigerator and the instrument will be well maintained. They will be available for experiments with the support of in-house instrument scientists. We expect that the dilution refrigerator and the high-field instrument will be used for at least 20 years.The high-field instrument will generate fields (transverse and longitudinal to the muon spin polarization) up to 10T. The dilution refrigerator will allow temperatures as low as 25mK. The entire instrument including the cryostat has been specifically designed based on a detailed simulation of a muon spin rotation experiment in a high magnetic field and low temperature environment. To obtain minimum impact on the muon trajectory and highest possible decay positron detection efficiency, the magnet is very compact and has horizontal warm bore. Equipping the magnet with a dilution refrigerator is crucial for the experiments included in this proposal. The dilution refrigerator is inserted horizontally in one of the two ports. It has its own vacuum vessel with dimensions (e.g. outer radius) optimized to allow for an efficient detection of the decay positrons. The positrons are detected by a segmented detection system surrounding the sample chamber. The system has been specially developed at PSI to fulfill all the requirements for a high field, low temperature measurement (high time resolution, small detector radius) [1,2]. The instrument with the dilution fridge will be available at a dedicated surface muon beam line an PSI.The proposed instrument with dilution refrigerator will allow new experiments in a wide range of scientific fields. These include quantum and frustrated magnetism, unconventional and high-temperature superconductors (including the recently discovered iron-based superconductors), multiferroic materials, magnetic and superconducting organic materials and magnetic semiconductors This proposal includes a few specific projects in these fields, that illustrate the usefulness and importance of this instrument. K. Sedlak et al. Physica B (2009), in press: http://dx.doi.org/10.1016/j.physb.2008.11.215. A. Stoykov et al., to be published in Nucl. Instruments and Methods A (2009).