\contentsline {section}{\numberline {1}Executive summary}{3}
\contentsline {subsection}{\numberline {1.1}Recommendations}{3}
\contentsline {subsection}{\numberline {1.2}Summary of the reasoning behind the recommendations}{3}
\contentsline {section}{\numberline {2}Expected performance of the LCGT SPI}{4}
\contentsline {subsection}{\numberline {2.1}Suspension Model}{4}
\contentsline {subsection}{\numberline {2.2}Observation band seismic noise}{6}
\contentsline {subsection}{\numberline {2.3}RMS motion}{6}
\contentsline {subsubsection}{\numberline {2.3.1}Displacement RMS}{6}
\contentsline {subsubsection}{\numberline {2.3.2}Hierarchical control}{7}
\contentsline {subsubsection}{\numberline {2.3.3}Speed RMS}{8}
\contentsline {section}{\numberline {3}Heat link vibration isolation}{9}
\contentsline {subsection}{\numberline {3.1}Heat-link design}{9}
\contentsline {subsection}{\numberline {3.2}Estimated vibration introduced from the heat-links}{10}
\contentsline {subsection}{\numberline {3.3}Cryogenic active vibration isolation}{10}
\contentsline {subsection}{\numberline {3.4}Conclusion for heat-link vibration isolation}{11}
\contentsline {section}{\numberline {4}Lock acquisition}{12}
\contentsline {subsection}{\numberline {4.1}LCGT lock acquisition procedure}{12}
\contentsline {subsection}{\numberline {4.2}Obstacles for arm cavity lock}{13}
\contentsline {subsubsection}{\numberline {4.2.1}Impulse limit velocity for mass lock acquisition}{13}
\contentsline {subsubsection}{\numberline {4.2.2}Ringing velocity}{14}
\contentsline {subsubsection}{\numberline {4.2.3}Radiation pressure}{14}
\contentsline {subsubsection}{\numberline {4.2.4}Arm lock simulation}{15}
\contentsline {subsection}{\numberline {4.3}Advanced lock acquisition techniques}{15}
\contentsline {subsubsection}{\numberline {4.3.1}Offset locking}{15}
\contentsline {subsubsection}{\numberline {4.3.2}Green laser pre-lock}{16}
\contentsline {paragraph}{Benefits of green laser pre-lock}{17}
\contentsline {subsection}{\numberline {4.4}Conclusion for lock acquisition}{17}
\contentsline {section}{\numberline {5}Vacuum tubes}{17}
\contentsline {section}{\numberline {A}Design of the LCGT Suspension Point Interferometer}{19}
\contentsline {subsection}{\numberline {A.1}Working Principle}{19}
\contentsline {subsubsection}{\numberline {A.1.1}Rigid Bar Picture}{20}
\contentsline {subsection}{\numberline {A.2}Design of the LCGT SPI}{20}
\contentsline {subsubsection}{\numberline {A.2.1}Interferometer Configuration}{20}
\contentsline {subsubsection}{\numberline {A.2.2}Location of SPI in the Suspension Chain}{22}
\contentsline {subsubsection}{\numberline {A.2.3}Suspension Design}{23}
\contentsline {subsubsection}{\numberline {A.2.4}Noise Requirement}{24}
\contentsline {paragraph}{Thermal noise of suspension:}{25}
\contentsline {paragraph}{Thermal noise of mirror:}{25}
\contentsline {paragraph}{Coil driver noise:}{25}
\contentsline {paragraph}{Shot noise:}{26}
\contentsline {subsubsection}{\numberline {A.2.5}Input Optics}{26}
\contentsline {subsubsection}{\numberline {A.2.6}Comments on technical feasibility}{27}
\contentsline {section}{\numberline {B}Members of the working group}{28}
\contentsline {section}{\numberline {C}Acronyms}{28}