> Oh dear god, no [...] Lead makes the cheapest and best shield.
Oh my, definitely no :-) Do not use lead for neutron shielding. You're thinking gamma radiation but then we're talking apples vs oranges then. You want atoms comparable in size to neutrons, so something with plenty of hydrogen. Think water or PET (plastic) when you don't want water to "leak" when transporting a source. For thermal neutrons maybe PET impregnated with boron. Now neutrons may generate gamma when captured by hydrogen, then you may want some lead for secondary effects like that but I am not sure how strong those are.
Lead is fine for shielding of sufficiently energetic neutrons, which can lose energy to lead by inelastic nuclear collisions. But below the threshold for that lead does very little.
Maybe as a special case then as a thin layer before following up with water or PET, or PET impregnated with boron. But would also need an extra layer following it for secondary gamma emission from neutron capture.
Oh my, definitely no :-) Do not use lead for neutron shielding. You're thinking gamma radiation but then we're talking apples vs oranges then. You want atoms comparable in size to neutrons, so something with plenty of hydrogen. Think water or PET (plastic) when you don't want water to "leak" when transporting a source. For thermal neutrons maybe PET impregnated with boron. Now neutrons may generate gamma when captured by hydrogen, then you may want some lead for secondary effects like that but I am not sure how strong those are.