BL 8.2 MIRROR UPGRADE

1
BL 8.2 MIRROR UPGRADE

• Front End Mirrors 8.2.1 (M101) and
• 8.2.2 (M201)

2
Reasons for replacement

• To take advantage of improved beam quality after
  implementation of top-off-mode.

3
Scope of Review

• New plug and play replacement design to
  minimize down time by performing installation on
  two day shutdown.

4
Differences between the new mirrors and the old

• New mirrors are longer to reduce the effects of
  the mirror benders on the ends of the mirror.
• New mirrors are of a two piece, frit bonded
  design, with internal cooling.
• Optical surface roughness will be improved.
• New mirrors will have new, external to vacuum,
  mirror bending, enabling fine tuning of mirror
  radius in operation.

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Existing Mirrors
6
New Mirrors
7

• BENDING DRIVE

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CALCULATION OF TORQUE REQUIREMENTS FOR BL 8.2.1
MIRROR BENDER

• Given
• The horizontal mirror spring for the bender must
  provide a torque of 7750 ounce inches to each
  end of the mirror in order to bend it to the
  correct radius.
• Find
• Suitable motor and gearhead to deliver required
  torque with a factor of safety near twice the
  required torque.
• Solution
• A Parker step motor will generate 65 oz.-in. of
  torque, however a clutch will limit this torque
  to 50 oz.-in. A 501 gearhead with an efficiency
  of 85 will be used to raise the 50 oz.-in. to
  2125 oz.-in.
• The gearhead will drive a drive screw with a
  thread pitch of 5/8-18. While this thread will
  provide a further mechanical advantage of 331,
  its efficiency is only about 17, which is
  reduced to 5.61. This will increase the torque
  delivered to 11,900 oz.-in.
• This delivered torque provides a factor of safety
  is 1.54.

9

• WATER COOLING

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SPRING DEFLECTION
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STRONGBACK DEFLECTION