The final turn of the J-PARC extracted proton beam is a superconducting combined
function magnet line. The combined function magnets are dipole cable magnets, typical
of cold mass collared magnets, but have been designed to include a large component of
quadrupole field. This provides both bending and focussing of the proton beam prior to
target impact, where neutrinos will be produced.
The BNL Superconducting Magnet Division is using its direct wind facility to produce
superconducting corrector magnets to be used in conjunction with the combined function
The first direct wind magnet set designed and fabricated is a
combined function magnet
with an additional skew dipole. This magnet is intended to be used within the cable collared
combined function dipole used for the extraction line. By design, the combined function
corrector is magnetically orthogonal to the main magnet, preventing large induced voltages
within the corrector when the main magnet quenches. This corrector is complete, and is
currently included within the first full length test magnet at KEK.
The second corrector style contains both a dipole and a skew dipole. These coil sets are
being made using the single wire conductor. These
interconnect corrector magnets
are to be located between the main combined function magnets. Four of these units will be fabricated,
the prototype coilset is being wound.