Interaction region magnets for VLHC

The interaction region (IR) magnets for the proposed Very Large Hadron Collider (VLHC) require high gradient quadrupoles and high field dipoles for high luminosity performance. Moreover, the IR magnets for high energy colliders and storage rings must operate in an environment where the amount of energy deposited on superconducting coils is rather large. In the case of doublet IR optics with flat beams, the design of the first 2-in-1 quadrupole defines the geometry and pole tip field in this and other IR magnets. This paper will present a novel design of this magnet that allows a very small separation between the two apertures. A brief discussion of the conceptual magnetic design of this and other magnets for interaction regions is given. The influence of critical current density in superconductor (a higher value of which is most beneficial to high performance IR magnet design) is also discussed. Since high temperature superconductors (HTS) retain most of their critical current density at high fields and at elevated temperatures, they offer an attractive possibility for the IR magnet designs of future colliders or upgrades of present colliders.