From 324683e4d28858f33dae80f4750793044b478d9e Mon Sep 17 00:00:00 2001
From: Jameson Graef Rollins <jrollins@finestructure.net>
Date: Mon, 21 May 2018 16:07:25 -0700
Subject: [PATCH] suspension: clean up fiber type handling
---
gwinc/suspension.py | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/gwinc/suspension.py b/gwinc/suspension.py
index c5e62ec..a17dc45 100644
--- a/gwinc/suspension.py
+++ b/gwinc/suspension.py
@@ -48,8 +48,8 @@ def suspQuad(f, ifo, material='Silica'):
material used for test mass suspension stage. steel used for all
other stages. Violin modes are included.
- fiberType = suspension sub type 0 => round fibers, otherwise ribbons
-
+ ifo.Suspension.FiberType should be: 0=round, 1=ribbons.
+
hForce, vForce = transfer functions from the force on the TM to TM
motion these should have the correct losses for the mechanical
system such that the thermal noise is:
@@ -73,9 +73,6 @@ def suspQuad(f, ifo, material='Silica'):
stages by K.Arai.
"""
- # default arguments
- fiberType = 0
-
# Assign Physical Constants
g = scipy.constants.g
kB = scipy.constants.k
@@ -171,14 +168,14 @@ def suspQuad(f, ifo, material='Silica'):
N3 = ifo.Suspension.Stage[1].NWires # Number of wires in stage 1
N4 = ifo.Suspension.Stage[0].NWires # Number of wires in stage 1
- if ifo.Suspension.FiberType == 0:
+ if ifo.Suspension.FiberType == 0: # Round
r_fib = ifo.Suspension.Fiber.Radius
xsect = pi * r_fib**2 # cross-sectional area
II4 = r_fib**4 * pi/4 # x-sectional moment of inertia
mu_v = 2 / r_fib # mu/(V/S), vertical motion
mu_h = 4 / r_fib # mu/(V/S), horizontal motion
tau_si = 7.372e-2 * rho * C * (4*xsect/pi) / K # TE time constant
- else:
+ elif ifo.Suspension.FiberType == 1: # Ribbon
W = ifo.Suspension.Ribbon.Width
t = ifo.Suspension.Ribbon.Thickness
xsect = W * t
@@ -186,6 +183,8 @@ def suspQuad(f, ifo, material='Silica'):
mu_v = 2 * (W + t)/(W*t)
mu_h = (3 * N4 * W + t)/(N4*W + t)*2*(W+t)/(W*t)
tau_si = (rho * C * t**2) / (K * pi**2)
+ else:
+ raise Exception("Unsupported suspension type: {}".format(ifo.Suspension.FiberType))
# loss factor, last stage suspension, vertical
phiv4 = phi_si * (1 + mu_v * ds)
--
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