ACB scatter with various materials
8/16/13
Arm cavity power, W
radius of baffle edge, m
radius of baffle bend, m
length of baffle plate edge, m
length of baffle bend, m
laser wavelength, m
wave number, m^-1
IFO waist size, m
solid angle of IFO mode, sr
ACB displacement @ 100 HZ, m/rt HZ
Transfer function @ 100 Hz, ITM HR
Gaussian beam radius at ITM, m
IFO arm length, m
PSL laser power, W
Arm Power, W
radius of Cryopump aperture, m
half-angle from centerline to Rcp, rad
BRDF, sr^-1; CSIRO, surface 2, S/N 2
radius of manifold/cryo baffle, m
height of ledge, m
radius of ACB hole, m
area of ACB hole, m^2
area of manifold/cryo baffle ledge, m^2
area of exposed ACB, m^2
power through the cryopump baffle aperture (hits
the arm cavity baffle), W
Area of cryopump baf aperture, m^2
incident intensity, W/m^2
tilt angle of baffle edge, rad
incident angle, rad
input angle range, bend, rad
input angle range, front edge, deg
input angle range, edge rad
input angle range, edge deg
Frontal area of baffle plate edge, m^2
incident power, W
BRDF #4 Oxidized stainless steel, 3 deg inc.
Reflectivity of baffle surface
break-over angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
BRDF #4 Oxidized stainless steel, 57 deg inc.
Reflectivity of baffle surface
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
BRDF Black Glass 57 deg inc.
specular reflectivity
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
BRDF Black Glass 15eg inc.
specular reflectivity
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
BRDF Black Glass 5 deg inc.
specular reflectivity
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
BRDF Black Glass fire polish (empirical estimate)
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
Black Glass BRDF Summary
Black Glass Reflectance Summary
BRDF DLC 5 deg inc.
specular reflectivity
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
BRDF DLC 15 deg inc.
specular reflectivity
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
BRDF DLC 57 deg inc.
specular reflectivity
break-over angle, rad
micro-roughness angle, rad
max BRDF, sr^-1
final slope modifier
micro-roughness constant
large angle
BRDF function, sr^-1
back-scatter angle, rad
back-scatter BRDF, sr^-1
DLC BRDF Summary
back-scatter BRDF, sr^-1
incident angle
back-scatter BRDF
DLC Reflectance Summary
Reflectance
incident angle
ReflectanceDF
OXIDIZED SS
incident angle, rad
Scatter function from baffle plate edge
Scattered power into IFO from baffle plate edge
displacement noise @ 100 Hz, m/rtHz
Scatter from baffle bend
Power Scatter from baffle bend into IFO
ACB displacement @ 100 HZ, m/rt HZ
displacement noise @ 100 Hz, m/rtHz
Power Scattered from the louver portion of baffle
displacement noise @ 100 Hz, m/rtHz
total displacement noise @ 100 Hz, m/rtHz
MIXED: OXIDIZED STEEL EDGE, BLACK GLASS LOUVER
Scattered power into IFO from baffle plate edge
Scattered power into IFO from baffle plate edge
ACB displacement @ 100 HZ, m/rt HZ
displacement noise @ 100 Hz, m/rtHz
Scatter function from baffle bend, oxidized steel
Power Scatter from baffle bend into IFO
ACB displacement @ 100 HZ, m/rt HZ
displacement noise @ 100 Hz, m/rtHz
Power Scattered from the louver portion of baffle, black glass
displacement noise @ 100 Hz, m/rtHz
Total Power Scattered from the edge, bend, and louver, black glass
total displacement noise @ 100 Hz, m/rtHz
ALL BLACK GLASS
Scattered power into IFO from baffle plate edge
ACB displacement @ 100 HZ, m/rt HZ
displacement noise @ 100 Hz, m/rtHz
displacement noise @ 100 Hz, m/rtHz
Scatter function from baffle bend, black glass
Power Scatter from baffle bend into IFO
ACB displacement @ 100 HZ, m/rt HZ
displacement noise @ 100 Hz, m/rtHz
Power Scattered from the louver portion of baffle, black glass
displacement noise @ 100 Hz, m/rtHz
Total Power Scattered from the edge, bend, and louver, black glass
total displacement noise @ 100 Hz, m/rtHz
Comparison of Baffle Materials
REFLECTED ACB SCATTER
reflectivity of black glass @ 57 deg
reflectivity of black glass @ 3 deg
net reflectivity of all black glass after 4 bounces
reflectivity of stainless steel @ 57 deg
reflectivity of stainless steel @ 3 deg
net reflectivity of ss after 4 bounces
net reflectivity of mixed black glass and ss after 4 bounces
power through the cryopump baffle aperture (hits
the arm cavity baffle), W
Area of cryopump baf aperture, m^2
incident intensity, W/m^2
area of exposed ACB, m^2
power hitting ACB, W
BRDF of chamber wall
Power reflected from mixed bg
Power scattered into IFO mode from ACBporc, W
Motion of BSC chamber @ 100 Hz, m/rt Hz
displacement noise @ 100 Hz, m/rtHz
Power reflected from ss baffle, W
Power scattered into IFO mode from ACBss, W
Motion of BSC chamber @ 100 Hz, m/rt Hz
displacement noise @ 100 Hz, m/rtHz