= Milestone =
===== two Pcals before installation of cryogenic payload at X and Y end =====

Development phase of Pcal
 1. Estimate the laser position due to minimal elastic deformation
 * Define the optical design of periscope
  *Define the diameters of mirrors for periscope
  *CAD drawing(step file)
  *Beam simulation using ZEMAX
  *Scattering simulation using Light Tools
  *Decision of mirrors(Thorlabs)
  *Decision of final design of periscope
 *Development of periscope
  * Vacuum test in KEK (outgas; need Baking?)
  * Optical test using low class laser
 *Decision of PCAL design
  *KAGRA Pcal emitter design (Discussion with Prof.Rick)
  *KAGRA Pcal receiver design (Discussion with Prof.Rick)
  *Simulation of end to end optical path
 *Decision of window specification

 *Decision of Periscope installation

 *Copy from Gold standard to Working standard for KAGRA

 *Make optical table for integrating sphere calibration in Toyama uni.