MBI_treshold correction

ring.L instead of ring.L0

CollectiveEffect/instabilities.py

@@ -37,7 +37,7 @@ def MBI_threshold(ring, sigma, R, b):
     Ia = 4*pi*epsilon_0*m_e*c**3/e # Alfven current
     chi = sigma*(R/b**3)**(1/2) # Shielding paramter
     xi = 0.5 + 0.34*chi
-    N = (ring.L0 * Ia * ring.ac * ring.gamma * ring.sigma_delta**2 * xi *
+    N = (ring.L * Ia * ring.ac * ring.gamma * ring.sigma_delta**2 * xi *
         sigma**(1/3) / ( c * e * R**(1/3) ))
     I = N*e/ring.T0