[Spaceships] Magsail Braking

[Joseph Paul]

Sol is in the middle of the Local Fluff (~on the order of a few light years across) which is in the middle of the Local Bubble (~300LY across). The Local Fluff has twice the Interstellar Medium (.1 atoms/cc) that the Local Bubble has (.05 atoms/cc) but the Local Bubble has something like 10% of the ISM that the rest of the Orion Arm exhibits (.5 atoms/cc). Differences in ISM density may affect propulsion systems that use the ISM and there may be a need to make adjustments when in the Orion Arm/Local Bubble/Local Fluff locales. Of course if your setting is a 'galaxy far, far away' you can set the ISM density to your own satisfaction.

Any thoughts?

EDIT

Ah Teviet! Thanks for a formula that illustrates what I just wrote. So the effectiveness of the braking is cut to 10% of what it is in a standard ISM when used in the Local Bubble. In the Local Fluff it would be at 20% of the standard ISM. What units is the ISM expressed in?

Ignore the above. I assumed that ISM would be set at a whole integer. So my question is again how is the ISM expressed?