Development of LHC low-/spl beta/ quadrupole magnets at KEK

Development of low-/spl beta/ quadrupole magnets for the LHC beam interaction regions has been carried out. The magnet is designed with a field gradient of 240 T/m in a coil aperture of 70 mm, and is to be operated at /spl les/215 T/m with absorption of beam loss heating. Three 1-m models with the final design have been developed and tested with satisfying requirements of field quality and training characteristics. A full-scale (6.3-m) prototype has been developed, and is being tested. Progress of the LHC low-/spl beta/ quadrupole development at KEK is reported.