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The current PRG is not 14.5 but 11, which is given with a safety factor of 6. Even with a safety factor of 3, the gain cannot be 29 since the arm reflectivity is not unity. The maximum PRG derived from the finite arm reflectivity is indeed 14.5. (K.Somiya, 6/8) The current PRG is not 14.5 but 11, which is given with a safety factor of 6. Even with a safety factor of 3, the gain cannot be 29 since the arm reflectivity is not unity. The maximum PRG derived from the finite arm reflectivity is indeed 14.5. More information is [[LCGT/subgroup/ifo/ISC/TaskList/CurrentStatus/ClassicalNoise/issue6|here]].(K.Somiya, 6/8)

To do list to define new parameters

It is important to review past parameters and pick up problems to determine new parameters. Known problems are listed here.


  • Safety factor of power on BS is 6, not 3 which was assumed before, so that PR gain can be increased up to 29 instead of 14.5.
  • Arm power was defined by sum of both arm powers. It should be a stored power of single arm.
  • How to determine an exact length of arm, for anti resonance of sidebands?
  • How to determine exact RF frequencies, for HOM of MC2?
  • Total inject power was defiened by only carrier power. It should be defined by carrier and sidebands.
  • Do we need pick off ports? Design of 2007 assumed a pick of between PRM and BS. It won't be existing in the new design, but how about pick off for X arm and Y arm? Should we use AR reflections as the pick off?
  • Redesign of length of MC2 for switching between BRSE and DRSE.
  • How much power is acceptable for single photo diode?
  • Determine macroscopic PRC length and SRC length. It is important to provide these length to the vacuum subgroup to determine the vacuum tube length.


Comments

> Safety factor of power on BS is 6...

The current PRG is not 14.5 but 11, which is given with a safety factor of 6. Even with a safety factor of 3, the gain cannot be 29 since the arm reflectivity is not unity. The maximum PRG derived from the finite arm reflectivity is indeed 14.5. More information is here.(K.Somiya, 6/8)

LCGT/subgroup/ifo/ISC/TaskList/CurrentStatus/ToDo (last edited 2009-06-09 16:12:42 by OsamuMiyakawa)