Concerns with Respect to QUAD LI20 901

Quad L120 901 is approximately 3.4 m after Section 20-8C and 5.6 m before Section 21-1B. (There is no Section 21-1A.) The quad has an aperture radius of r=0.01378 m and an effective length of L=0.1068 m. With the present linac 50-GeV lattice it is run at a nominal strength of BDES=GL=(B/r)L=79.738 kG. Thus the field at the pole tip is B=10.288 kG and the maximum possible dipole strength under any condition (i.e., short or no short) with the quad strength at its nominal value, which in fact will occur only at the pole tip, is BL=BL{sup max}=1.0988 kG-m or 0.10988 T-m. A dipole will bend the beam according to: {theta}[rad] = 0.3 {integral} Bdl[T-m]/cp[GeV]. Thus the maximum possible bending angle will occur for a beam just grazing the pole tip, i.e., {theta} {approx} 1 mrad for a 33 GeV (at Sector 20) beam.