Since all these particles are coming from the same direction (while in interplanetary flight) why not just point the craft so that the fuel tank is between the crewed space and the sun?
The design is flawed, however, in that it assumes that the incoming protons in an SPE are highly directional and so really provides only a sector-type shield configuration. In fact, the energetic protons that arrive initially are highly directional, but the spectrum quickly becomes isotropic before any significant dose is received. Hence, assuming that one can point a sector shield in some particular direction and effectively shield from SPE protons arriving from all directions is just not a valid assumption.
That extra mass is still painful enough that lots of designs skip the whole matter and call solar particle events a known risk that can't be mitigated.
Radiation shielding is heavy. It blocks lower-energy particles, like the ones emitted from the Sun in great quantities when there's a solar particle event, much better than the steady background of high-energy galactic cosmic rays. Blocking GCRs is nearly pointless, because you need kg/cm of shielding (tens of meters of solid material) to block out most of the incident energy. Blocking solar particle event radiation is much easier, both because tens of grams per square centimeter is sufficient, and because generally you have some warning (20-60 minutes) of an event, which occurs only for hours or days; Tight spaces are permissible.Even so, tens of grams per square centimeter multiplies vehicle mass by a large factor. Workable solar storm shelters rely on several tons of ECLSS water supply shunted into plastic bags, and only seal off a small closet-sized compartment within the habitat rather than trying to cover the whole thing. That extra mass is still painful enough that lots of designs skip the whole matter and call solar particle events a known risk that can't be mitigated.I got to thinking, though - on interplanetary spacecraft like MCT we already have lots of mass available to act as shielding; It's already serving duty as propellant. Methane and LOX need to spend most of their time in a thermally privileged position at 90K for zero-boiloff, well away from the 300K human accommodations, but twelve hours of boiloff is easy to accommodate in the grand scheme of things. Slotting the habitat, or a small part of the habitat, into an array of propellant tanks (or an internal tank), and putting on some extra clothing and turning on some extra heaters, seems like a way to have your cake and eat it too.So this thread is about designs that do that.A few possibilities:A) 6 to 18 long tanks, stacked hexagonally, with a center tank missing. Slot in a tank-sized habitat in the center spot when it's time to shelter. Bring water curtains in the walls full of liquid water, and you might not even have to heat the thing actively due to 273K freezing buffer.B) One large tank, with an internal bulb welded in. Keep at 90K until need arises, then heat internal bulb to 270K and dock to hab. Possibly use for food cold storage.C) One large tank, with a narrow unpressurized internal passageway welded in, making the tank roughly toroidal. Move skinny heated hab in on rails when needed. Possibly use as navigable passageway to module on other side of tank.Edit:D) Small empty tanks surround the hab at all times, and are filled using a pump from the propellant tanks during a storm
There was a recent article on CERN (I think it was) developing a SC magnetic shield for radiation.