@PhdThesis{dbt_mods_00026983,
  author = 	{Voigt Dr.-Ing., Jens},
  title = 	{Entwicklung eines Messsystems zur Charakterisierung magnetisch geschirmter Umgebungen},
  year = 	{2015},
  month = 	{Dec},
  day = 	{08},
  keywords = 	{MSR; magnetisch geschirmter Raum; SQUID; absolute magnetische Flussdichte},
  abstract = 	{A number of experiments in fundaments in fundamental physics, such as the
search of the electric dipole moments in atoms and particles, are limited
by the uncertainty contributed from the magnetic properties of the
environment. Hence, these magnetic properties have to be characterized
carefully to allow further optimizations of the experiment. Sensors for
such magnetic characterizations are typically limited by the magnetic
noise, the frequency bandwidth, the absolute magnetic accuracy for flux
densities below 1 nT and the dimensions of the measurements system.
This theses deals with the development, characterization and application of
a new, compact and mobile multi-channel measurement system called Cube-II
with performance suitable for characterizing the magnetic properties of
magnetically shielded rooms. The Cube-II-system is based on 16 individual
low temperature superconducting quantum interference devices (SQUIDs)
inside a nonmagnetic cylindrical dewar with 30 cm in diameter and 31 cm in
height. With this dewar, a measurement time of up to 20 hours is reached.
During this time, a white noise level of less than 6 fT/sqrt(Hz) was
achieved for all 16 SQUID magnetometers in a frequency range of 1 Hz to
above 15 kHz. Below 1 Hz, the magnetic flux noise increases up to 5
pT/sqrt(Hz) below 1 mHz. One special feature of the Cube-II-system,
compared to typical multichannel SQUID-systems, is the possibility to
estimate simultaneously the three vector and nine gradient components of
the absolute magnetic flux density inside magnetic shielded rooms. 
Due to the high accuracy of the mechanical parts of the measurement setup,
the three vector components of the residual magnetic field inside the
heavily magnetic shielded room BMSR-2 were estimated with an expanded
uncertainty of plus minus 8 pT for Bx and By and plus minus 23 pT for Bz.
By using a new arrangement of the SQUIDs on the surface of a cube, two
methods can be used to estimate the nine components of the magnetic field
gradient. By using the first and well known method (shift method) to shift
the Cube-II along the X-, Y- and the Z-axes of the magnetic shielded room,
an expanded uncertainty for this method of below plus minus 2 pT/cm were
achieved. For the second method (intrinsic method) the new arrangements of
at least 12 SQUIDs were used to estimate the nine components with an
expanded uncertainty of less than plus minus 11pT/cm.},
  url = 	{https://www.db-thueringen.de/receive/dbt_mods_00026983},
  url = 	{http://uri.gbv.de/document/gvk:ppn:842564519},
  file = 	{:https://www.db-thueringen.de/servlets/MCRZipServlet/dbt_derivate_00032798:TYPE},
  language = 	{de}
}