DOLLY Developments

The continuous extension and improvement of the experimental capabilities of the MuSR spectrometers, allows them to remain competitive in the modern fast-paced scientific landscape, while serving the needs of the MuSR research community. To this aim, also for the Dolly spectrometer we plan a series of incremental improvements, as well as the addition of new features.

An upgrade to silicon photomultiplier (SiPM) detectors will provide a more compact detection system, with a better time resolution, and a lower sensitivity to external magnetic fields. The final goal here is to access higher internal magnetic fields.

This development, currently under test, will allow us to mount multiple samples simultaneously and then measure them sequentially. Considering that each sample mounting and cool down takes many hours, this will enhance the efficiency of beam time use, while reducing the consumption of liquid helium (particularly high during the initial cool-down procedure).

We evaluate the possibility to double the current field limit (from 150 to 300 G) which would enable TF-muSR experiments, in particular, in single-crystal samples, without the need to reorient them.

The increased muon-beam deviation at higher fields would have to be suitably compensated by a detector and sample translation system.

In collaboration with TU Dresden and the MPI Dresden we have developed a piezoelectric-driven uniaxial pressure cell for muon spin relaxation experiments which is utilized for first experiments in Dolly. We plan to further develop this strain cell towards higher pressures, robustness and user friendliness.