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I work in a cyclotron facility manufacturing FDG. Recently all of my whole body badge readings are 0 and ring badge averages around 3 mSv.
Is this normal ?
When I first started I usually had 0.19 to 0.3 on whole body but the last 8 readings are 0.
Obviously the lower the better but I’m surprised my whole body badge hasn’t registered anything.

I've been doing a little research into duoplasmatrons recently (mostly for fun), and I'm a little confused about what the intermediate electrode is doing.

I understand that the duoplasmatron is using a glow discharge and that most of the ions are created near the anode as a result. I understand that the intermediate electrode is at a lower voltage than the anode. I understand that (apparently) some of discharge goes to the intermediate electrode and some of the discharge goes to the anode. I understand that a magnetic field keeps the ions confined in that area between the intermediate electrode and anode, presumably so that more ionization occurs and to focus the direction of the ion's motion. I understand that some of the ions end up on the opposite side of the anode, and that additional electrodes help focus and propel those ions into the rest of the particle accelerator.

I'm just struggling to understand why the intermediate electrode is needed for that process. Is there a reason the anode would not be sufficient by itself, or with a negative electrode on the opposite side to accelerate the ions like a mini ion-thruster? Is the intermediate electrode acting like an electrostatic lens for the electrons because it's "more negative" than the anode? Is the shape of the intermediate electrode, combined with the gas inlet and heat from the discharge, creating a pressure differential that accelerates the ions past the anode like the combustion chamber of a rocket engine?

This is starting to bug me, so if anyone could explain it to me, I'd appreciate it.

In the coming months, we're looking to unload our storage from over the years. Our KN's are looking to be decommissioned sometime in 2026 so we'll be looking for some takers later, but for now we have a lot of old Vandegraff parts up for grabs shortly.

We got:

• Terminal and column stuff
• lots of 6" gasketed beamline pieces and stuff
• Diffusion pumps and stuff
• Quadrapoles and optics stuff
• Couple of belts and stuff

The cost is you pay for the shipping, and this offer is only to people who need it. They don't make this stuff anymore.

If you know anyone who needs parts, let me know.

Greetings Fellow Users,

I am working with the STCyclotron example (from the advanced category of the Geant4 distribution) to simulate radionuclide production. The code runs, and I can generate output files and ROOT plots without issue. Before relying on the Monte Carlo results, however, I am trying to validate the configuration against basic physical expectations. I’ve run into a puzzling inconsistency that I have not been able to resolve.ISSUE: For simulations where the beam radius ≤ target radius, and the total proton current remains fixed, I obtain significantly different end-of-bombardment activities when I change either: These changes produce large differences in the integrated activity reported in Output_ParentIsotopes.txt, even though the total number of incident protons is the same in all runs. For example, given a fixed target radius of 3.0 mm, this is what I get when I vary the spot beam radius: 3.0 mm radius → 292.6 mCi 2.5 mm radius → 348.9 mCi 2.0 mm radius → 431.2 mCi From my understanding, in the ideal case, for a sufficiently thick, uniform target that stops all protons, the total number of nuclear reactions should not depend on the beam spot size. A smaller beam should simply produce a more concentrated activation distribution, but the total number of reactions should be the same as long as: I had in mind results similar to that found in Figure 4 of (Yu and Chen 2025) https://doi.org/10.1016/j.radphyschem.2025.112695

the target radius (beam radius fixed), or

the beam radius (target radius fixed).

the beam is fully intercepted by the target,

the beam current and irradiation time are unchanged, and

proton stopping and nuclear cross sections do not depend on lateral position.

figure 41722×1303 185 KB

Could it be that activity integration in STCyclotron might be scaling with the entire target geometry rather than the irradiated area, but I have not yet identified where in the code this occurs. Thank you in advance for any insight.

Geant4 Version: 11.3.2
Operating System: Linux
Compiler/Version: Ubuntu
CMake Version:

I’ve got an old HVEE 2.5 MeV Tandetron and a GE PETtrace. I’d love to know if there is anyone in this sub can help troubleshoot.

Hey everybody, l'm an electrical engineering student and really want to major in accelerator control, any advice?

Just say the magnet or some other crucial part fails, what will happen to the stored energy inside the synchrotron? Will it all cause a bright flash and explode? Or will it get absorbed by something inside? Also, what happens if the particle emitter still works but the actual accelerator stops working?

Fermi's PIP-II project is on the move. Here's the cold box arriving on-site in the wee hours of Dec. 21st.

More info here: https://pip2.fnal.gov/coldbox/

Hey! I'm about to go to ORNL for an USPAS session later this month. Anybody got anything neat I should try to see or do? Either at Oak Ridge or in general nearby?

I won't have that much free time... But still.

Anyone know anything about these guys? https://emerald-horizon.com/

They seem to be touting an accelerator driven sub critical thorium reactor. They are light on details but I infer from information elsewhere that the idea might be a laser driven accelerator. That's the bit of their tech I am most interested in.

Presumably they're starting with protons onto a light element target if it's a very compact. Anyone know anything about details of the accelerator?

The Thomas Jefferson National Accelerator Facility in Newport News, VA is having its biennial open house tomorrow Saturday June 8 from 9am-3pm, admission and parking is free. Learn about superconducting materials, supercomputers, particle accelerators, particle detectors, nuclear physics research and much more. See our web page for more information.

Who makes a relatively 'off the shelf' 70+ MeV cyclotron? Preferably capable of helium beams as well as protons. I know IBA do, but are there alternatives?

The Thomas Jefferson National Accelerator Facility in Newport News, VA is having its biennial open house on Saturday June 8 from 9am-3pm, admission and parking is free. Learn about superconducting materials, supercomputers, particle accelerators, particle detectors, nuclear physics research and much more. See our web page for more information.

I am an EE student and I need EPICS control app for my project. I am using Windows and can't figure out how i will download this. I have been looking for an answer for a week :( I hope this is the right subreddit. Thanks!