\chapter{Assembling suspension chains for A+ at LHO}
\label{A}
In 2019 I spent some months working on LIGO Hanford site. Along with the study exposed in Chapter 5, I offered my lab experience in building the HSTS (HAM Small Triple Suspension) to be installed for the LIGO A+ upgrade. The assembly team was composed by me, Dr. Rahul Kumar and Dr. Jeff Bartlett. The suspensions have been installed in 2021 under the supervision of Rahul in HAM7 and HAM8, and will be known as Filter Cavities (FC). The FC will enhance squeezing capabilities and help improve the quantum noise. Here there is a gallery of original photos of the lab-work done together. It was an intense and very interesting team work, which enhanced my skills in working into a clean room, with delicate structures that needed to be assembled very precisely.

\begin{figure}
\centering
\includegraphics[scale=1]{images/blades.jpg} \includegraphics[scale=0.8]{images/blades2.jpg}
\caption[Mounting the blades]{Mounting the blades onto the top of the suspension skeleton. On the right photo: the blades mounted and fixed and the required angle.}
\end{figure}

\begin{figure}
\centering
\includegraphics[scale=0.7]{images/wire.jpg} \includegraphics[scale=0.6]{images/tension.jpg}
\caption[Preparing the suspending wires]{Left: one of the wire used to suspend the test mass. The wires suspending the bottom mass are stainless steel wires, 0.0047 inches-thick. The upper stages are suspended by 0.008 inches-thick wires. Right: Technique to prepare the wire with the right tension: a given weight is applied and left for 5 minutes.}
\end{figure}

\begin{figure}
\centering
\includegraphics[scale=1]{images/support.jpg} \includegraphics[scale=1]{images/wiresupinstall.jpg}
\caption[Mounting the wires and their support]{Mounting the wires for the test mass suspension on their support.  Right: Jeff and I while installing the wire support into the suspension cage.}
\end{figure}

\begin{figure}
\centering
\includegraphics[scale=2.2]{images/TMinstall.jpg}\\

\includegraphics[scale=2.2]{images/Rahul.jpg}
\caption[Installing the test masses]{Top: Rahul and I installing the bottom test mass and suspending it with the wires. The bottom mass is a mirror of 2.8 Kg. Bottom: Rahul while measuring the alignment of the test mass into the suspension cage.}
\end{figure}




