From 4828e7b9fe3493dbe169a86c800808ea5807fdad Mon Sep 17 00:00:00 2001
From: Lee McCuller <Lee.McCuller@gmail.com>
Date: Tue, 14 Aug 2018 16:26:11 -0400
Subject: [PATCH] moved fixes to sus in aLIGO.yaml to A+.yaml to fix sus noise
curve
---
gwinc/ifo/A+.yaml | 53 +++++++++++++++++++++++++++++++++--------------
1 file changed, 38 insertions(+), 15 deletions(-)
diff --git a/gwinc/ifo/A+.yaml b/gwinc/ifo/A+.yaml
index 07555d8..290077f 100644
--- a/gwinc/ifo/A+.yaml
+++ b/gwinc/ifo/A+.yaml
@@ -38,6 +38,18 @@ Infrastructure:
polarizability: 7.8e-31 # m^3
TCS:
+ # The presumably dominant effect of a thermal lens in the ITMs is an increased
+ # mode mismatch into the SRC, and thus an increased effective loss of the SRC.
+ # The increase is estimated by calculating the round-trip loss S in the SRC as
+ # 1-S = |<Psi|exp(i*phi)|Psi>|^2, where
+ # |Psi> is the beam hitting the ITM and
+ # phi = P_coat*phi_coat + P_subs*phi_subs
+ # with phi_coat & phi_subs the specific lensing profiles
+ # and P_coat & P_subst the power absorbed in coating and substrate
+ #
+ # This expression can be expanded to 2nd order and is given by
+ # S= s_cc P_coat^2 + 2*s_cs*P_coat*P_subst + s_ss*P_subst^2
+ # s_cc, s_cs and s_ss were calculated analytically by Phil Willems (4/2007)
s_cc: 7.024 # Watt^-2
s_cs: 7.321 # Watt^-2
s_ss: 7.631 # Watt^-2
@@ -68,18 +80,20 @@ Seismic:
Suspension:
Type: 'Quad'
- FiberType: 'Round'
+ FiberType: 'Tapered'
BreakStress: 750e6 # Pa; ref. K. Strain
Temp: 290
+ # VHCoupling:
+ # theta: 1e-3 # vertical-horizontal x-coupling (computed in precompIFO)
Silica:
- Rho : 2200 # Kg/m^3;
+ Rho : 2.2e3 # Kg/m^3;
C : 772 # J/Kg/K;
K : 1.38 # W/m/kg;
Alpha : 3.9e-7 # 1/K;
dlnEdT: 1.52e-4 # (1/K), dlnE/dT
Phi : 4.1e-10 # from G Harry e-mail to NAR 27April06 dimensionless units
- Y : 72e9 # Pa; Youngs Modulus
+ Y : 7.2e10 # Pa; Youngs Modulus
Dissdepth: 1.5e-2 # from G Harry e-mail to NAR 27April06
C70Steel:
@@ -100,8 +114,8 @@ Suspension:
Phi: 1e-4
Y: 187e9
- # ref ---- http://design.caltech.edu/Research/MEMS/siliconprop.html
- # all properties should be for T ~ 20 K
+ # ref http://www.ioffe.ru/SVA/NSM/Semicond/Si/index.html
+ # all properties should be for T ~ 120 K
Silicon:
Rho: 2329 # Kg/m^3; density
C: 300 # J/kg/K heat capacity
@@ -109,9 +123,9 @@ Suspension:
Alpha: 1e-10 # 1/K thermal expansion coeff
# from Gysin, et. al. PRB (2004) E(T): E0 - B*T*exp(-T0/T)
# E0: 167.5e9 Pa T0: 317 K B: 15.8e6 Pa/K
- dlnEdT: -2.0e-5 # (1/K) dlnE/dT T=20K
+ dlnEdT: -2e-5 # (1/K) dlnE/dT T=120K
Phi: 2e-9 # Nawrodt (2010) loss angle 1/Q
- Y: 1.558e11 # Pa Youngs Modulus
+ Y: 155.8e9 # Pa Youngs Modulus
Dissdepth: 1.5e-3 # 10x smaller surface loss depth (Nawrodt (2010))
# Note stage numbering: mirror is at beginning of stack, not end
@@ -122,6 +136,9 @@ Suspension:
Stage:
# Stage1
- Mass: 39.6 # kg; current numbers May 2006 NAR
+ # length adjusted for d = 10mm and d_bend = 4mm
+ # (since 602mm is the CoM separation, and d_bend is accounted for
+ # in suspQuad, so including it here would double count)
Length: 0.59 # m
Dilution: .nan #
K: .nan # N/m; vertical spring constant
@@ -161,9 +178,12 @@ Suspension:
Width: 1150e-6 # m
Fiber:
- EndLength: 4.5e-02
- EndRadius: 4e-04
- Radius: 2.05e-04
+ Radius: 205e-6 # m
+ # for tapered fibers
+ # EndRadius is tuned to cancel thermo-elastic noise (delta_h in suspQuad)
+ # EndLength is tuned to match bounce mode frequency
+ EndRadius: 400e-6 # m; nominal 400um
+ EndLength: 45e-3 # m; nominal 20mm
## Optic Material -------------------------------------------------------
Materials:
@@ -173,14 +193,15 @@ Materials:
## Dielectric coating material parameters----------------------------------
Coating:
## high index material: tantala
- Yhighn: 124e9
- Sigmahighn: 0.28
+ Yhighn: 124e9 # LMA (Granata at LVC) 2017 (was 140)
+ Sigmahighn: 0.28 # LMA (Granata at LVC) 2017 (was 0.23)
CVhighn: 2.1e6 # Crooks et al, Fejer et al
Alphahighn: 3.6e-6 # 3.6e-6 Fejer et al, 5e-6 from Braginsky
Betahighn: 1.4e-5 # dn/dT, value Gretarrson (G070161)
ThermalDiffusivityhighn: 33 # Fejer et al
- Phihighn: 9.0e-5 # tantala mechanical loss
Indexhighn: 2.06539
+ Phihighn: 9.0e-5 # tantala mechanical loss
+ Phihighn_slope: 0.1
## low index material: silica
Ylown: 72e9
@@ -189,8 +210,9 @@ Materials:
Alphalown: 5.1e-7 # Fejer et al
Betalown: 8e-6 # dn/dT, (ref. 14)
ThermalDiffusivitylown: 1.38 # Fejer et al
- Philown: 1.25e-5 # silica mechanical loss
Indexlown: 1.45
+ Philown: 1.25e-5 # silica mechanical loss
+ Philown_slope: 0.4
## Substrate Material parameters--------------------------------------------
Substrate:
@@ -213,11 +235,12 @@ Laser:
## Optics------------------------------------------------------------------
Optics:
+ Type: 'SignalRecycled'
PhotoDetectorEfficiency: 0.9 # photo-detector quantum efficiency
Loss: 37.5e-6 # average per mirror power loss
BSLoss: 0.5e-3 # power loss near beamsplitter
coupling: 1.0 # mismatch btwn arms & SRC modes; used to
-
+ # calculate an effective r_srm
SubstrateAbsorption: 0.5e-4 # 1/m; bulk absorption coef (ref. 2)
pcrit: 10 # W; tolerable heating power (factor 1 ATC)
Quadrature:
--
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