Under Imperial Starfire rules, I have a few questions about minefields:
A ship enters a minefield and does not conduct any further movement that turn, as it knows there are mines there. Using its XRs, it realizes that all of the surrounding hexes, with the exception of the hex it came from there are also mines. On the following turn, it turns 180 degrees (to go back to the unmined hex). Do the mines attack it during that next turn?
1) The Mines would attack when the unit entered the minefield
2) The Mines would attack when the unit turned around (assuming a "quick-turn", if it turned around 1 hex-side at a time, it would be attacked each time it turned).
3) The Mines would attack when the unit left the minefield
04.18.02.2 Target Selection, Minefield: Active minefields will attack any large spacecraft that move into their range, which is 0 (the same hex as the MF) for all current MF types. Unlike other weapons, minefields execute their attacks in the movement phase of the turn, at the end of the movement impulse in which their target(s) entered, exited, or spent a movement point in place in their hex. If a non-friendly unit enters the range of an active unknown minefield, the owning player does not announce the presence of the mines until all movement has been completed for that impulse. As soon as all movement is completed, the minefield immediately attacks. A non-moving unit, such as a base that has been towed into range or a starship that has lost its drive, will be attacked by the minefields once on the first movement impulse of each turn that they are in range. (See 27.08.05 for minefield rules.)
Should a ship that does not have energy weapons but has XR and 'D's attempt to do minesweeping operations?
Sure, if it has a large enough, and good enough, suite of Point Defense, i.e., enough to engage all attacking patterns with with a '10' chance to intercept.
Does a Dz count as a 'D' for the purposes of minesweeping operations (or for that matter, count as a D vs. fighters/small craft)?
Yes to both
Are there any formulas to calculate optimal force packages against a minefield of a given size?
Actually, the size of the minefield has no bearing on the design of the Minesweeper. Regardless of the size of the Minefield each pattern will fire 1 mine per 10 HS in size of its target. The pattern will fire a minimum of 10 mines (so a 30 HS DD will still be targeted by 10 mines) and a maximum of 50 mines (so a 300 HS Super-Monitor will still only be attacked by 50 mines). Each pattern fires as a separate volley, so Point-Defense is available for each pattern (assuming it isn't destroyed by a previous pattern). Each pattern will attack once until there are no more targets, and a unit cannot be engaged more than once until all targets have been engaged once.
Thanks a lot!