B-52H.
The Vulcan appears to be a Mk. 2, as it is too early for either the MRR or tanker versions, and it has the larger wing and fat/long ECM tailcone.
Sure is, XH535 was the third production B.2 completed, served with the Aeroplane and Armament Experimental Establishment (A&AEE) at the time the picture was taken, was also one of the first Vulcan B.2s to be lost in an accident, crashing in 1964, after only four years in service.