Alignment of CDF Quads

1
Alignment of CDF Quads

• CDF would like to see the IP moved vertically by
  -500 um an Horizontally by -200 um.
• CDF would like to see the angle of the beams
  changed by -400 urad Vertically, and by -180 urad
  Horizontally
• The CDF Detector is sinking at a rate of about 1
  mm per year.
• The Tevatron Department would like to reduce
  strengths in the correction elements and center
  the beam in the apertures.

2
As founds of the CDF Low Beta Quad
elevations The rest of the Tevatron is at 40.6
inches on this plot, or where the outer most
elements on this plot are shown.
3
Slide showing possible Vertical Quad Moves (next
slide)

• Moves the IP and slope by approximately the
  desired amount.
• Beam trajectory approximately follows the the
  alignment of the Quadrupoles.
• Correction elements between A48 and B11 go to
  zero current.

4
Vertical IP moves by -.44 mm Vertical angle
changes by -170 urad
5
Maximum output is .12 mrad
Large Vertical Corrections
6
IP is lowered by 1.1 mm Vert angle change is -50
urad
Horizontal IP moves by -.26 mm Horizontal angle
changes by -150 urad

• Alternative solution with smaller Quad moves
• IP move is larger than desired, but angle change
  is smaller than desired
• Correction elements go to zero current between
  A47 and B14
• Horizontal correction also shown here.

7
Small Vertical corrections
8
Comparison of Two Vertical Solutions

1. Large change better matches CDFs requests
2. Beam position changes within the Quad apertures
   are a maximum of 1.9 mm in the small change
   solution, and a maximum of 3.5 mm in the large
   change solution.
3. Correction elements strength go to zero farther
   out into the arcs in the small change solution.
4. The beam goes into the Low Beta Quad region lower
   in the small change solution (position lower in
   separators). The Quads and Separators are
   already Low in this region.
5. As CDF continues to sink, the collision point
   will move toward the center of the detector if we
   go with the small change corrections.
6. We chose the small change solutions because of
   points 2, 3, and 4.

9
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10
Horizontal Correction element changes at flattop
and at low beta for the chosen Quad moves
11
Vertical Quadrupole Alignment
Quad End As found (inches) New Position (inches) Change (inches)
AQ2 up 40.463 40.455 -.008
AQ2 dn 40.459 40.451 -.008
AQ3 up 40.464 40.436 -.028
AQ3 dn 40.451 40.439 -.012
AQ4 up 40.450 40.468 .018
AQ4 dn 40.427 40.472 .045
BQ4 up 40.483 40.448 -.035
BQ4 dn 40.485 40.450 -.035
BQ3 up 40.491 40.461 -.030
BQ3 dn 40.478 40.460 -.018
BQ2 up 40.477 40.446 -.031
BQ2 dn 40.467 40.436 -.031
12
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13
Horizontal Quadrupole Alignment
Quad End As found (inches) New Position (inches) Change (inches)
AQ2 up -.011 .013 .024
AQ2 dn -.016 .008 .024
AQ3 up -.019 -.003 .016
AQ3 dn -.033 -.002 .031
AQ4 up .019 0 -.019
AQ4 dn .003 0 -.003
BQ4 up -.065 -.022 .043
BQ4 dn -.069 -.018 .051
BQ3 up -.036 -.003 .033
BQ3 dn .009 .002 -.007
BQ2 up -.018 .004 .022
BQ2 dn .011 .002 -.009
14
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