Measurement of magnetic permeability of steel laminations of Booster   gradient magnets
  New experiments at Fermilab require higher beam intensities at Booster, resulting in higher influence of magnet steel on the beam. In order to carefully take these effects into account it is necessary to know geometric and material properties of magnets. This work is dedicated to the measurement of magnetic permeability of steel laminations of Booster gradient magnets as a complex function of frequency in the frequency range from several megahertz up to 1 GHz. The magnetic permeability is estimated by analyzing S-parameters of microstrip lines made up from laminated steel. 
Yury Tokpanov, Valeri Lebedev, William Pellico
physics.acc-ph