ColdFire75

http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/beam.htm

Says the protons reach 0.999999991 times the speed of light.

The milky way is about 9.5x10²⁰ meters in diameter.

So the difference is 9.5x(10²⁰⁾ -9.5x(10²⁰⁾ *0.999999991

Or just 9.5x(10²⁰⁾ x(1-0.999999991)

Which is 8 550 000 000 000 m

Or about 60 times the distance from earth to the sun, or 1.4 times the distance from the sun to pluto