Unshielded SQUID Sensors for Ultra-Low-Field Magnetic Resonance Imaging

Research output: Contribution to journalArticleScientificpeer-review


Research units

  • Elekta Oy
  • VTT Technical Research Centre of Finland


We have implemented a new field-tolerant low-critical-temperature superconducting quantum interference device current sensor with submicrometer Josephson junctions. The small junction area enables the fabrication of devices with lower sensor noise and higher tolerance against magnetic fields. An application benefitting from these properties is ultra-low-field magnetic resonance imaging (ULF MRI). In the currently ongoing BREAKBEN project, new technology is being pushed forward by combining ULF MRI with magnetoencephalography in a single instrument. We describe the sensor architecture aimed for this purpose and justify the guidelines behind the design. Experimental characterization reveals that, with the aid of reasonable amount of heating, unshielded sensor operation after high magnetic pulses at least up to 150 mT appears to be possible.


Original languageEnglish
Article number1600204
Number of pages4
JournalIEEE Transactions on Applied Superconductivity
Issue number4
Publication statusPublished - 1 Jun 2018
MoE publication typeA1 Journal article-refereed

    Research areas

  • flux trapping, magnetoencephalography, Superconducting quantum interference device, ultra-low-field magnetic resonance imaging

ID: 17473234