| 104 | [[latex($\theta_2 = \int_{R}^{r_o} B_0 2 \pi r dr = \pi B_0(r_o^2 - R^2)$)]] |
| 105 | |
| 106 | this second integral is the flux as measured before the field has been distorted (i.e. when R=r_i). |
| 107 | |
| 108 | Setting these 2 fluxes equal and solving for r_i gives |
| 109 | |
| 110 | [[latex($r_i = \frac{r_o^2 + R^2}{2r_o}$)]] |
| 111 | |
| 112 | Plugging in for r_o found above gives |
| 113 | |
| 114 | [[latex($r_i = R \frac{(\beta_{ram} + 1)}{\sqrt{4 \beta_{ram}}}$)]] |
| 115 | |
| 116 | which is approximately |
| 117 | |
| 118 | [[latex($r_i \approx R \sqrt{\frac{\beta_{ram}}{4 }}$)]] |
| 119 | |
| 120 | or |
| 121 | |
| 122 | [[latex($\boxed{r_i \approx \frac{1}{2}r_o}$)]] |
| 123 | |
| 124 | or |
| 125 | |
| 126 | [[latex($\boxed{r_i \approx 3R}$)]] |