#accelerators

Today's idiot moment: why is it not finding a stable beam size? I was using the first point of my parameter scan, which had focussing=0. So there is no stable beam size. #physics #accelerators

1 inch aperture Halbach dipole #magnet made of off-the-shelf permanent magnet cuboids and a 3D printed holder. This has a central field of 0.34 Tesla, would be 0.5 Tesla with more longitudinal slices. #physics #accelerators

As well as cables, they're now removing all these non-radioactive pipes from the tunnel behind the underground laboratory. #accelerators #physics

I've also been told that the vacuum in my chamber seemed bad because the vacuum gauge was faulty! #physics #accelerators

Abandoned equipment at the High Energy Accelerator Research Organization (KEK) in Tsukuba. #physics #accelerators #science
https://x.com/john_kon/status/1897251991925239906

Complicated graph of the day. It shows instability rates as a function of three field parameters in a ring containing a Coulomb crystal. The green band is most stable. #physics #accelerators

The cake that looks like RF cavities. #physics #accelerators
RT https://x.com/kek_jp/status/1896758161161466150

All of a sudden I am looking for a 68030 accelerator for the Amiga 2000. There are a few modern ones in different states of readiness, it seems.

Can anyone point me to something solid? (Older would be fine - but I see none on offer in the regular places.)

#Amiga #Commodore #CommodoreAmiga #Amiga2000 #AmigaDOS #vintagecomputing #retrocomputing #vintagetech #accelerators #CPU #Motorola MC68030

Can you get two totally different particles to have the same optics in the same place at the same time? I think this note shows it is possible, at least approximately. #physics #accelerators #iontraps
https://stephenbrooks.org/ap/report/2025-3/ponderomotive.pdf

The plug for the electron gun has appeared on the outside of the chamber too. #physics #accelerators

We may have a vacuum leak, but the electron gun test for my ion trap experiment is in the vacuum chamber now. Screens aren't at an ideal viewing angle but I should be able to see something. #physics #accelerators

Asking WolframAlpha for the eigenvalues of a coupled 4x4 stability matrix. #physics #accelerators Actually, this was very informative and explained why my beam might be unstable (there's a space charge intensity stop band, it becomes stable again at higher intensities!)

Weirdest paper title I've seen in a while. #physics #accelerators
https://pubs.aip.org/aip/rsi/article-abstract/91/6/063303/958785/A-feasibility-study-of-zebrafish-embryo?redirectedFrom=fulltext

While designing a ring to hold Coulomb crystals, I found a magnetic field model I used at first worked quite well after some parameter tuning, but when I tried to improve it by removing nonlinearities, the results got worse and the beam was more unstable! #physics #accelerators

Also the focussing behaviour doesn't seem to correspond to the linear transfer matrix, I may have made a mistake somewhere.

Spent this week trying to remove the sextupole from a magnetic field model, which resulted in everything else breaking. #physics #accelerators

Ran this over the weekend with improved parameters. Coulomb crystal is still kind of solid in this ring after 1/16 sec. #physics #accelerators

CERN transports 70 protons across site in a truck. #physics #accelerators
https://home.cern/news/news/experiments/base-experiment-takes-big-step-towards-portable-antimatter

First principles calculation of the force between two moving charged particles. #physics #accelerators
https://stephenbrooks.org/ap/report/2024-12/spacecharge_rel.pdf

It looks like there's a small range of velocities (for a fixed ring magnetic field and superperiod) where my Coulomb crystal's heating instability is suppressed. This one is kind of holding it together after 2500 turns. Will continue running... #physics #accelerators

(This is the result of uninspired manual fiddling around with parameters and leaving a different simulation running each day for the last couple of weeks.)

Start of HL-LHC (high luminosity LHC) delayed by approximately one year, to June 2030. Improves schedule contingency, lots of work being done in Long Shutdown 3.
#physics #accelerators
https://home.cern/news/opinion/accelerators/updated-schedule-cerns-accelerators