1 / 10

KAGRA Vacuum System: Optical Baffles in Beam Tubes

This document provides details about the layout and manufacturing process of optical baffles in the beam tubes of the KAGRA Vacuum System. It includes information on the required properties of the baffles and their manufacturing specifications.

mbandy
Download Presentation

KAGRA Vacuum System: Optical Baffles in Beam Tubes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. KAGRA Vacuum System 130801　VAC (YS) • 1. Layout (interferometer and survey map) • **tilting the optical plane of interferometer • for draining water. • **horizontal floors in each room prepared for installing chambers. • **position of chamber/mirror is to be described in “map coordinates (survey map) of tunnel” EYC EYV Xopt EYA horizontal plane at X end Y-arm optical plane of interferometer X arm x IYA IYC IYV y O (BS) horizontal plane at center room MC Yopt PRM BS X-arm Y arm horizontal plane at Y end IXC IXV IXA EXA EXC EXV SRM

  2. KAGRA Vacuum System 130801　VAC (YS) 1. Layout (KAGRA location) Geodetic coordinates: Latitude, Longitude, Height (B, L, H+He) H; radius of GRS80 of ellipsoid earth Hg; height of geoid surface from GRS80 surface Z Xmap Japan rectangular plane coordinate: survey map (Xmap, Ymap, Ho) Ymap Takayama origin, zone VII, Japan Ho: height from geoid surface B 3D terrestrial coordinate: KAGRA optical plane (X, Y, Z) He (ellipsoid height) = Ho(orthometric height) + Hg (geoid height) Y H X L • GRS80

  3. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes • Number of baffles in the 3-km long arm • Every 24-m, or longer, along the arm, 40-mm in height, 54-degree tilted • Requirement: baffle surface (coating) • Specular reflection <10% @1064 nm，0-60 deg incidence • Total scattering <2% @1064, 12deg incidence • Surface roughness Ra <several microns or less • Mechanical and thermal durability (film) • Flexural strength of plated film: JIS H8504 • Thermal shock strength: JIS H8504 • Friction proof: JIS H8503 • Vacuum performance • Outgassing rate <3x10-7 Pa m3 s-1m-2

  4. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes Structure PCD = φ810 R h = (D-d)/2 = 40 mm θ= 36° D=798 d=720 w

  5. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes Manufacturing process • 1) Stainless steel sheet (SUS304 BA) of 0.8 mm thick • 2) Laser cutting for sector shape andserrated edge • 3) Rolling and welding for conicalshape（frustum) • 4) Removing oxidized layer of weld beads • 5) “Solblack” plating • alkaline degreasing • electrolytic cleaning • acid cleaning • Ni plating (5 mm) • Solblack plating (15 mm) • chemical treatment for blacking • thermal treatment (190°C 2.5hrs, in air) • 6) Vacuum firing (220-250°C 4hrs, in vacuum)

  6. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes Manufacturing process • 1) Stainless steel sheet (SUS304 BA) of 1 mm thick • 2) Laser cutting for sector shape andserrated edge • 3) Rolling and welding for conicalshape（frustum) • 4) Removing oxidized layer of weld beads • 5) “Solblack” plating • alkaline degreasing • electrolytic cleaning • acid cleaning • Ni plating (5 mm) • Solblack plating (15 mm) • chemical treatment for blacking • thermal treatment (190°C 2.5hrs, in air) • 6) Vacuum firing (220-250°C 4hrs, in vacuum)

  7. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes • Properties of “solblack coating” • Specular reflection <10% @1064 nm，0-60 deg incidence • Total scattering <2% @1064, 12deg incidence • Surface roughness Ra <several microns or less • Mechanical and thermal durability (film) • Flexural strength of plated film: JIS H8504 • Thermal shock strength: JIS H8504 • Friction proof: JIS H8503 • Vacuum performance • Outgassing rate <3x10-7 Pa m3 s-1m-2

  8. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes • Properties of “solblack coating” • Specular reflection <10% @1064 nm，0-60 deg incidence • Total scattering <2% @1064, 12deg incidence • Surface roughness Ra <several microns or less • Mechanical and thermal durability (film) • Flexural strength of plated film: JIS H8504 • Thermal shock strength: JIS H8504 • Friction proof: JIS H8503 • Vacuum performance • Outgassing rate <3x10-7 Pa m3 s-1m-2 Total scattering including specular reflection @ 8 deg incidence

  9. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes • Properties of “solblack coating” • Specular reflection <10% @1064 nm，0-60 deg incidence • Total scattering <2% @1064, 12deg incidence • Surface roughness Ra <several microns or less • Mechanical and thermal durability (film) • Flexural strength of plated film: JIS H8504 • Thermal shock strength: JIS H8504 • Friction proof: JIS H8503 • Vacuum performance • Outgassing rate <3x10-7 Pa m3 s-1m-2

  10. KAGRA Vacuum System 130801　VAC (YS) 2. Optical baffles in beam tubes • Properties of “solblack coating” • Specular reflection <10% @1064 nm，0-60 deg incidence • Total scattering <2% @1064, 12deg incidence • Surface roughness Ra <several microns or less • Mechanical and thermal durability (film) • Flexural strength of plated film: JIS H8504 • Thermal shock strength: JIS H8504 • Friction proof: JIS H8503 • Vacuum performance • Outgassing rate <3x10-7 Pa m3 s-1m-2 solblack: after vacuum baking

More Related