Muon Acceleration to 750 GeV in the Tevatron Tunnel for a 1.5 TeV mu+ mu- Collider

TL;DR

This paper explores a method to accelerate muons from 30 to 750 GeV in the existing Tevatron tunnel using two specialized rings, achieving high muon survival rates with innovative RF and magnet ramping techniques.

Contribution

It proposes a novel muon acceleration scheme in the Tevatron tunnel utilizing two rings with specific RF and magnet configurations for efficient acceleration.

Findings

Muon survival is 80% in the first ring.

Muon survival increases to 92% in the second ring.

The design minimizes civil construction and leverages existing tunnel infrastructure.

Abstract

Muon acceleration from 30 to 750 GeV in 72 orbits using two rings in the 1000m radius Tevatron tunnel is explored. The first ring ramps at 400 Hz and accelerates muons from 30 to 400 GeV in 28 orbits using 14 GV of 1.3 GHz superconducting RF. The ring duplicates the Fermilab 400 GeV main ring FODO lattice, which had a 61m cell length. Muon survival is 80%. The second ring accelerates muons from 400 to 750 GeV in 44 orbits using 8 GV of 1.3 GHz superconducting RF. The 30 T/m main ring quadrupoles are lengthened 87% to 3.3m. The four main ring dipoles in each half cell are replaced by three dipoles which ramp at 550 Hz from -1.8T to +1.8T interleaved with two 8T fixed superconducting dipoles. The ramping and superconducting dipoles oppose each other at 400 GeV and act in unison at 750 GeV. Muon survival is 92%. Two mm copper wire, 0.28mm grain oriented silicon steel laminations, and a low duty cycle mitigate eddy current losses. Low emittance muon bunches allow small aperatures and permit magnets to ramp with a few thousand volts. Little civil construction is required. The tunnel exists.