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1. Feb 10, 2016

### Raptor112

1. The problem statement, all variables and given/known data
Consider the following disturbances. Clearly state for 10 keV electrons if any of the three adiabatic invariants violated, and justify your answer?
(i) The magnetic field at L = 6.5 (~geo-stationary orbit) steadily changes strength and direction from one state to another in a time of less than 40 minutes during a substorm.
Hint: the condition for non-violation is that $\tau_{ disturbance} / \tau_{ invariant} >>1$
It is useful to quantify “>>” : for this problem sheet please express the condition as
$\tau_{ disturbance} / \tau_{ invariant} >>10$

2. Relevant equations
Bounce Period $= L R_{E} (\frac{W}{M})^{-0.5}(3.7 -1.6 sin(\alpha_{eq}))$
Drift Period $= \frac{{2}q B_E R_E ^2}{3LW}\frac{1}{0.7+0.3sin\alpha_{eq}}$
Gyro Period $= \frac{qB}{m}$

3. The attempt at a solution
Not sure what value of $\alpha_{eq}$ to use?

2. Feb 12, 2016

### jasonRF

What are the two extremes for the periods of interest (ie when the sin term is +1 or -1)?