Interaction Region Analysis for A High-Field Hadron Collider
Abstract
The primary goal of the interaction region (IR) is to demagnify the transverse beam dimension to a small spot size at the interaction point (IP) to reach the required luminosity. With an experimental drift space of +/-25 m and a quadrupole focusing strength of 360 T/m at the triplets, a beta* of 0.1 m can be achieved at a beam energy of 50 TeV. Only two families of sextupoles are needed to globally correct the chromaticity. Since the momentum spread of the beam is small (sigma(p) approximately 2 x 10 to the minus 5th power), a relatively large (about 20) linear chromaticity can be tolerated so that higher-order chromatic aberration produced by the low-Beta* optics is negligible. With a crossing angle of 70 mur and a beam separation of 5 sigma, the required minimum aperture of the triplet magnets is about 3 cm. The luminosity reduction resulted from such a crossing angle is about 13%. Crab crossing can be used to further reduce beta* to below 0.05 m. At the same time, luminosity degradation caused by the angle crossing is eliminated. With crab cavities positioned near the triplet operating at a voltage of a few MV, the required voltage of the 379 MHz storage rf system can be reduced from the nominal 100 MV to below 10 MV. The requirements on the accuracy of the positioning of the crab cavities and the operating voltage are both moderate. More than two families of sextupoles are needed for global chromatic compensation only when beta* approaches 0.05 m and below.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1996
- Accession Number
- ADA355107
Entities
People
- Glen P. Goderre
- Jie Wei
- Stephen G. Peggs
Organizations
- Brookhaven National Laboratory