Describe KAGRA/Subgroups/VIS/OpsManual/FishingRods here.

This page describes the status of the fishing rods.

Beam splitter

Top filter

• Range:

  • LVDT: [ -2500 , +4900 ] µm (7694).

  • Stepper motor: [ -1,400,000 , +1,400,000 ] steps (7694).

  • Temperature when measured:

• Observations:

  • At 25 ºC it was possible to use the fishing rod to set the keystone at nominal position (8125).

  • at 24.5 ºC or colder it was not (8645, 11465).

Standard Filter

• Range:

  • LVDT: [ -700 , +700 ] µm (3558).

  • Stepper motor: [ -870,000 to +835,000 ] steps (3558).

  • Temperature when measured:

• Observations:

  • It's been at its lowest position since the temperature was 25 ºC (8125, 8645).

  • We set the keystone to 488 µm and couldn't move it further down (8125, 8645).

Bottom filter

• Range:

  • LVDT: [ -1000 µm , +1800 ] µm (3280).

  • Stepper motor: [ -746,000 , +746,000 ] steps (3280).

  • Temperature when measured:

• Observations: this fishing rod doesn't seem to have any problems, but we haven't used it at every temperature condition we've had.

SR2

Top filter

• Range:

  • LVDT: [ -990 , 903 ] µm (8082).

  • Stepper motor: [ -1,700,000 , 1,500,000 ] steps (8082).

  • Temperature when measured:
• Observations:

Stardard filter

• Range:

  • LVDT: [ -750 , 1000 ] µm (4431).

  • Stepper motor: [ 300,000 , 1,000,00 ] steps (4431).

  • Temperature when measured:
• Observations:

Bottom filter

• Range:

  • LVDT: [ -500 , 600 ] µm (4430).

  • Stepper motor: [ -550,000 , -250,000 ] steps (4430).

  • Temperature when measured:
• Observations:

Other related entries

8082

SR3

Top filter

• Range:

  • LVDT: [ 885 , -1299 ] µm (7758).

  • Stepper motor: [ -500,000 , 1,100,000 ] steps (7758).

  • Temperature when measured:

• Observations: After pump down it was not possible to move the keystone to zero using the fishing rod. It went as high as -750 µm at the time (8135).

Standard Flter

• Range:

  • LVDT: [ -2000 , 2000 ] µm (4720).

  • Stepper motor: [ -700,000 , 1,100,000 ] steps (4720).

  • Temperature when measured:

• Observations:This fishing rod of not working at all (8135). It's a real shame because it had a large range of 4 mm total.

Bottom Filter

• Range:

  • LVDT: [ -1600 , +1000 ] µm (4654).

  • Stepper motor: [ -200,000 , 250,000 ] steps (4654).

  • Temperature when measured:

• Observations:

  • After pump down it was not possible to move the keystone to zero using the fishing rod. It went as high as -265 µm at the time 8658.

  • The number of steps for the stepper motor seem relatively small. In principle there's nothing wrong with this but let's point this out.

Other related entries

• 8658, 8135.

SRM

Top Filter

• Range:

  • LVDT: [ -865 , 626 ] µm (7857).

  • Stepper motor: [ -1,600,000 , 1,600,00 ] steps (7857).

  • Temperature when measured:

• Observations:

Standard Filter

• Range:

  • LVDT: [ -1,700 , 1,400 ] µm (4721) .

  • Stepper motor: [ -700,000 , 1,100,000 ] steps (4721) .

  • Temperature when measured:

• Observations:

Bottom Filter

• Range:

  • LVDT: [ -3,000 , 2,800 ] µm (4721).

  • Stepper motor: [ -600,000 , 800,000 ] steps (4721).

  • Temperature when measured:

• Observations: