From f7e970efb0f024c520b84025106335a9c4c40c28 Mon Sep 17 00:00:00 2001
From: Kevin Kuns <kevin.kuns@ligo.org>
Date: Sat, 14 Nov 2020 17:02:13 -0500
Subject: [PATCH] radiation pressure calculations use suspension instead of
free mass susceptibility
* All quantum calculations use the final stage suspension mass instead of calculating it from the test mass radius and thickness
* shotradSignalRecycled uses the suspension susceptibility instead of the free mass approximation
---
gwinc/ifo/noises.py | 10 ++++++----
gwinc/noise/quantum.py | 24 ++++++++++++------------
gwinc/squeeze.py | 3 +--
gwinc/suspension.py | 10 +++++++---
4 files changed, 26 insertions(+), 21 deletions(-)
diff --git a/gwinc/ifo/noises.py b/gwinc/ifo/noises.py
index f81bd594..e182cea6 100644
--- a/gwinc/ifo/noises.py
+++ b/gwinc/ifo/noises.py
@@ -132,19 +132,21 @@ def precomp_suspension(f, ifo):
pc.VHCoupling.theta = ifo.Suspension.VHCoupling.theta
else:
pc.VHCoupling.theta = ifo.Infrastructure.Length / const.R_earth
- hForce, vForce, hTable, vTable = suspension.suspQuad(f, ifo.Suspension)
+ hForce, vForce, hTable, vTable, tst_suscept = suspension.suspQuad(
+ f, ifo.Suspension)
pc.hForce = hForce
pc.vForce = vForce
pc.hTable = hTable
pc.vTable = vTable
+ pc.tst_suscept = tst_suscept
return pc
-def precomp_quantum(f, ifo):
+@nb.precomp(sustf=precomp_suspension)
+def precomp_quantum(f, ifo, sustf):
pc = Struct()
- mirror_mass = mirror_struct(ifo, 'ETM').MirrorMass
power = ifo_power(ifo)
- noise_dict = noise.quantum.shotrad(f, ifo, mirror_mass, power)
+ noise_dict = noise.quantum.shotrad(f, ifo, sustf, power)
pc.ASvac = noise_dict['ASvac']
pc.SEC = noise_dict['SEC']
pc.Arm = noise_dict['arm']
diff --git a/gwinc/noise/quantum.py b/gwinc/noise/quantum.py
index 260a1ae4..e3f6d36c 100644
--- a/gwinc/noise/quantum.py
+++ b/gwinc/noise/quantum.py
@@ -90,12 +90,12 @@ def getSqzParams(ifo):
######################################################################
-def shotrad(f, ifo, mirror_mass, power):
+def shotrad(f, ifo, sustf, power):
"""Quantum noise strain spectrum
:f: frequency array in Hz
:ifo: gwinc IFO Struct
- :mirror_mass: mirror mass in kg
+ :sustf: suspension transfer function struct
:power: gwinc power Struct
:returns: displacement noise power spectrum at :f:
@@ -120,12 +120,12 @@ def shotrad(f, ifo, mirror_mass, power):
######################################################################
# call the main IFO Quantum Model
- if 'Type' not in ifo.Optics:
- fname = shotradSignalRecycled
+ if 'Type' not in ifo.Optics or ifo.Optics.Type == 'SignalRecycled':
+ coeff, Mifo, Msig, Mn = shotradSignalRecycled(f, ifo, sustf, power)
+ elif ifo.Optics.Type == 'SignalRecycledBnC':
+ coeff, Mifo, Msig, Mn = shotradSignalRecycledBnC(f, ifo, power)
else:
- namespace = globals()
- fname = namespace['shotrad' + ifo.Optics.Type]
- coeff, Mifo, Msig, Mn = fname(f, ifo, mirror_mass, power)
+ raise ValueError('Unrecognized IFO type ' + ifo.Optics.Type)
# separate arm and SEC loss
Mnoise = dict(arm=Mn[:, :2, :], SEC=Mn[:, 2:, :])
@@ -221,7 +221,7 @@ def compile_SEC_RES_TF():
# Main IFO quantum models
######################################################################
-def shotradSignalRecycled(f, ifo, mirror_mass, power):
+def shotradSignalRecycled(f, ifo, sustf, power):
"""Quantum noise model for signal recycled IFO (see shotrad for more info)
New version July 2016 by JH based on transfer function formalism
@@ -242,7 +242,7 @@ def shotradSignalRecycled(f, ifo, mirror_mass, power):
L = ifo.Infrastructure.Length # Length of arm cavities [m]
l = ifo.Optics.SRM.CavityLength # SRC Length [m]
T = ifo.Optics.ITM.Transmittance # ITM Transmittance [Power]
- m = mirror_mass # Mirror mass [kg]
+ m = ifo.Suspension.Stage[0].Mass # Mirror mass [kg]
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bsloss = ifo.Optics.BSLoss # BS Loss [Power]
@@ -298,7 +298,7 @@ def shotradSignalRecycled(f, ifo, mirror_mass, power):
Omega = 2*pi*f # Signal angular frequency [rad/s]
h_SQL = sqrt(8 * hbar / (m * (Omega * L)**2)) # SQL Strain
- K = 16 * P * omega_0 / (m * c**2 * Omega**2)
+ K = - 16 * P * omega_0 / c**2 * sustf.tst_suscept
# arm cavity
exp_2jOmegaL_c = exp(2j*Omega*L/c)
@@ -391,7 +391,7 @@ def shotradSignalRecycled(f, ifo, mirror_mass, power):
return coeff, Mifo, Msig, Mnoise
-def shotradSignalRecycledBnC(f, ifo, mirror_mass, power):
+def shotradSignalRecycledBnC(f, ifo, power):
"""Quantum noise model for signal recycled IFO
See shotrad for more info.
@@ -423,7 +423,7 @@ def shotradSignalRecycledBnC(f, ifo, mirror_mass, power):
L = ifo.Infrastructure.Length # Length of arm cavities [m]
l = ifo.Optics.SRM.CavityLength # SRC Length [m]
T = ifo.Optics.ITM.Transmittance # ITM Transmittance [Power]
- m = mirror_mass # Mirror mass [kg]
+ m = ifo.Suspension.Stage[0].Mass # Mirror mass [kg]
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bsloss = ifo.Optics.BSLoss # BS Loss [Power]
diff --git a/gwinc/squeeze.py b/gwinc/squeeze.py
index 1dc304f8..6c33b63c 100644
--- a/gwinc/squeeze.py
+++ b/gwinc/squeeze.py
@@ -9,8 +9,7 @@ def sql(ifo):
c = const.c
power = ifo_power(ifo)
w0 = 2 * pi * c / ifo.Laser.Wavelength
- rho = ifo.Materials.Substrate.MassDensity
- m = pi * ifo.Materials.MassRadius**2 * ifo.Materials.MassThickness * rho
+ m = ifo.Suspension.Stage[0].Mass
Titm = ifo.Optics.ITM.Transmittance
Tsrm = ifo.Optics.SRM.Transmittance
tSR = sqrt(Tsrm)
diff --git a/gwinc/suspension.py b/gwinc/suspension.py
index b71cf7b4..bc7056a2 100644
--- a/gwinc/suspension.py
+++ b/gwinc/suspension.py
@@ -587,9 +587,13 @@ def suspQuad(f, sus):
# Calculate horizontal/vertical TFs with all losses on,
# for the vibration isolation calculation
- k = khr + 1j*(khi[:,0,:] + khi[:,1,:])
- hTable = top_displ_to_tst_displ(k, masses, f)
k = kvr + 1j*(kvi[:,0,:] + kvi[:,1,:])
vTable = top_displ_to_tst_displ(k, masses, f)
- return hForce, vForce, hTable, vTable
+ k = khr + 1j*(khi[:,0,:] + khi[:,1,:])
+ hTable = top_displ_to_tst_displ(k, masses, f)
+
+ # test mass susceptibility for radiation pressure calculations
+ tst_suscept = tst_force_to_tst_displ(k, masses, f)
+
+ return hForce, vForce, hTable, vTable, tst_suscept
--
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