Leiden University Student Repository

Plugge, Jaimy (2020)

Generating High B0-Fields for use in Extremely Low Temperature MRFM

Master thesis | Physics (MSc)

In this thesis, we address our progress to send high currents and generating high magnetic fields at milliKelvin temperatures for the use in MRFM measurements. Multiple ways for sending a current while at 20mK inside a dilution refrigerator are described. The use of a heatsink and an option for splitting the current over multifillament connections are analyzed and tested. We find starting resistances in our spotwelds contradicting with earlier measurements of 3pΩ conducted in our group. Next, the design of a transformer in the form of a cone complement is showed and preliminary tests are presented. Furthermore, the inductance is calculated from a sweep over a frequency range from 500Hz to 20kHz. Our measurements show high potential for an experiment to generate 500mT at 20mK. This experiment is described and in addition, a possible use for B1-fields of this cone complement coil is briefly discussed.

MRFM

MRI

Extremely Low Temperature

Magnetic Fields

High Currents

Persistent Current Switch

Author

Plugge, Jaimy

Faculty

Faculty of Science

Specialisation

Quantum Matter and Optics

Supervisors

Oosterkamp, Tjerk

ECTS Credits

3

Language

en