I have read that it is better to use materials like polyethylene for protection against space radiation as compared to lead. But I need transparent materials, so lead glass seemed like a good option. I will have a layers of other transparent materials over it, but will lead glass work or will it produced secondary radiation?
I haven't found specific research into lead glass for space applications. But the general principle that light atoms are better than heavy ones for shielding against space radiation also applies to lead glass.