From f4d6abe91386bf4063ae91703327e7edd52a88ab Mon Sep 17 00:00:00 2001
From: Gamelin Alexis <alexis.gamelin@synchrotron-soleil.fr>
Date: Mon, 19 Jun 2023 16:30:13 +0200
Subject: [PATCH] [Fix] Typo for vacuum impedance
---
mbtrack2/instability/instabilities.py | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/mbtrack2/instability/instabilities.py b/mbtrack2/instability/instabilities.py
index 195f035..8e3985e 100644
--- a/mbtrack2/instability/instabilities.py
+++ b/mbtrack2/instability/instabilities.py
@@ -5,7 +5,7 @@ General calculations about instability thresholds.
import numpy as np
import matplotlib.pyplot as plt
-from scipy.constants import c, m_e, e, pi, epsilon_0
+from scipy.constants import c, m_e, e, pi, epsilon_0, mu_0
import math
def mbi_threshold(ring, sigma, R, b):
@@ -308,7 +308,7 @@ def rwmbi_growth_rate(ring, current, beff, rho_material, plane='x'):
E0 = ring.E0
R = ring.L/(2*np.pi)
frac_tune, int_tune = math.modf(ring.tune[index])
- Z0 = 377.7 # Vacuum impedance [Ohm]
+ Z0 = mu_0*c
gr = (beta0*omega0*current*R) /(4*np.pi*E0*beff**3) * ((2*c*Z0*rho_material) / ((1-frac_tune)*omega0))**0.5
@@ -343,7 +343,7 @@ def rwmbi_threshold(ring, beff, rho_material, plane='x'):
E0 = ring.E0
tau_rad = ring.tau[index]
frac_tune, int_tune = math.modf(ring.tune[index])
- Z0 = 377.7 # Vacuum impedance [Ohm]
+ Z0 = mu_0*c
Ith = (4*np.pi*E0*beff**3) / (c*beta0*tau_rad) * (((1-frac_tune)*omega0) / (2*c*Z0*rho_material))**0.5
--
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