glc,
There are extremely high magnetic fields inside the ring, where the particles travel, yes, but there are also very high energy x-rays there as well! So, if I were inside the ring when the accelerator were running, I would very quickly receive a fatal does of radiation, depending on where I was. No one can be inside when it is running, and there are serious personnel interlocks in place to ensure that that never happens.
However, the electromagnetic waves I am concerned with come from the high voltage power supplies and associated electronics that power the linear accelerator section, as all of that stuff is fairly near the control room. The beam itself is one level down, and there is lots of shielding between the control room and it. But some of the electronics and power supplies are on the same level, and near-by.
I actually talked with one of the other accelerator operators who owns a cell phone, and he told me that he doesn't get reception until he is well away from the building, so I do not think that the lack of reception is due to interference from the HV power supplies and pulse forming network. And, come to think of it . . . I don't actually know what range of frequencies cell phones work at anyway! The main problem with the HV power supplies and pulse forming network is the fast switching on and off of various components, which almost certainly generate a range of EM interference.
Anyway, I'm rambling. I think I've decided to give the D3 a go and just chance it. If I can't use the headphone amp in the control room, so be it. I'll eventually be getting power speakers for that purpose anyway, as that is better than open headphones for enabling me to also hear alarms and alerts, (although open headphones work well enough at letting in outside sound.) So if the problem is only with the amp section, then it's probably a non-issue anyway.
