Yokozawa, Akutsu

Abstract

We have opened the IXA chamber; I'm sorry for my sudden decision. Many dusts were found in the chamber and the inner tower's surface. In addition, some pillars of the inner tower were rotten. I'm not well sure but the dog clamps fixing the inner tower were not properly used in my point of view, and should be re-worked.

Purpose

The NAB installation would start from June 6, but I did not know actual positions or alignment of the tower on which NAB suspension will sit, or the tolerances; let's call it inner tower. (I rather like to call Inoue-tower  ). To place the NAB suspension, the inner tower should be sufficiently rigid and balanced so that the amount of the adjusting work for the NAB suspension in the chamber would be minimized; note that the NAB suspension was already adjusted outside (in Mitaka). Anyway, considering the remainng time, I determined my mind to open the IXA chamber today.

Today's activities

• Today only one of the side flange was opened. Both of the flanges at the chambers side and the lid side were protected with white tapes (Nitto SPV-202). The o-ring was accidentally slipped off from the chamber-side flange, so Yokozawa-san wiped it with vectra-alpha + ethanol. We put it back to the flange's groove and then protected by the wite tape.
• Then I entered in the chamber. The area where I stepped on, I carpeted some aluminum foils.
• Due to the inner tower, entering into the chamber is more difficult than I thought (Fig. 1). Considering the final alignemnt of the NAB suspension, this would be a serious issue. In order to access the backside of the inner tower, probably I need to consider a ladder-like stuff from the top, when the top lid opens.
• Observing the inside, I found the surface of the inner tower was rotten (Fig. 2-4). I tried to wipe out them with vectra-alpha + ethanol, but they were stubborn. And a rather large plastic trash (Fig. 5).
• The inner tower itself was rigid, but I have no idea when the NAB suspension would sit on the inner tower.
• The dog clamps, which fixed the inner tower, seemed too oblique (Fig. 6 and 7). I like to set them properly...