Based on interviews with (legal and illegal) immigrants to Denmark, meetings with stakeholders and with experts in the field, this article addresses issues regarding the underground economy. Our findings show that, in Denmark, the existence of an underground economy makes it possible for semi-compliant and non-compliant immigrants to make a living. We suggest that the underground economy in Denmark will continue to provide networks of illegal residents with opportunities for informal economic activities as trust allows entrepreneurs to function below the radar, by owning enterprises registered using the names of people who are legally in this country.

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The Lawrence Berkeley National Laboratory (LBNL) Superconducting Magnet Group has completed the design, fabrication and test of HD1, a 16 T block-coil dipole magnet. State of the art Nb 3 Sn conductor was wound in double-layer racetrack coils and supported by an iron yoke and a tensioned aluminum shell. In order to prevent conductor movement under magnetic forces up to the design field, a coil pre-stress of 150 MPa was required. To achieve this level without damaging the brittle conductor, the target stress was generated during cool-down to 4.2 K by exploiting the thermal contraction differentials between yoke and shell. Accurate control of the shell tension during assembly was obtained using pressurized bladders and interference load keys. An integrated 3D CAD model was used to optimize magnetic and mechanical design and analysis.Index Terms-Nb 3 Sn, superconducting accelerator magnet.