Can you give me scientific references to mass loss during the pass over?

[Alex K]

Ah, he means the output, not the "stuff" inside, huh?
On that note, is there a way to figure out about what type of device or 'thing' would yield 0.7 grams?

Yes, in Nuclear fusion, something like couple of permille of mass energy is converted to blast energy, for fission it is a bit less. Look up that number for a device and divide .7 grams by it. E.g., if we assume 1 permille conversion just for concreteness, .7g energy output would correspond to an H-Bomb with 700g tritium or lithium or so in it (which sounds like little, so we're maybe not dealing with an fusion bomb... idk).

You could use Wolfram Alpha to directly convert 0.7 grams * c^2 into kilotons TNT...

OK I did that and my estimate wasn't that bad, 0.7 g mass equivalent corresponds to a yield of 15 kTons, i.e. an average fission device like in Hiroshima