We're Running Out of Electrons!

"It takes a damn long time to run an experiment.”

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Okay, we're not really running out of electrons.

Estimates say that Earth has approximately 3.6 times 10 raised to the 51 electrons. The number of particles we use during each beam run is some coefficient multiplied by 1,000,000,000 (10 to the power of 9). The odds that we run out of electrons in the forseeable future are basically nonexistent, yet it's become a bit of a subject of fascination to the SPEEDers that electrons are so disposable.

An electron gun supplies the entire DESY facility with all the electrons they need. DESY is an electron farm: somewhere in the world as you're reading this, electrons are being fired into a Linear Accelerator, reaching speeds of up to 99.9% the speed of light. Then, they go through a smaller loop called the PIA, and are directed where they're needed - whether that's PETRA III or our test beam, DESY II.

But wait! The average human body has around 10 raised to the 28 electrons. It's hilarious to me that something we're trying to study is so abundant in all of us - so valuable and invaluable all at once. It's become more and more apparent to me in the past few days that the beauty of physics lies in the fact that it is literally everywhere. Even if much of particle physics can't be observed with the human eye, there are so many things that we can see with direct parallels to phenomena in particle physics.

Take the lenses in your glasses, for example. Antonio explained this to us on the board (pen and paper, that's always where it begins):

The lenses in your glasses adjust the focus point of incoming light so it lines up with your retina. Their job is to focus - just like the quadrupole magnet in accelerators and beamlines, which helps focus the electron beam.

Another cool parallel - we use the Big Red Magnet to change the energy of our test beam. How? The magnet works like a prism - selecting only the electrons with the energy we want (which is usually either 4GeV or 1GeV, for us).

There's something to be said about studying something you'll never see with your naked eye. Physicists devote their lives to things they'll never get to witness the beauty of, from axions to single photons. It might be a bit silly of me, but I find this quite tragic.

The world feels like it's been in a standstill for the past ~2 weeks. I'm sure the teammates who are diligently keeping up with their homework might disagree, but I've managed to elude the stressors of school by not doing my homework. The daily DESY schedule goes something like this: we wake up at around 8, go to breakfast, round up the stragglers, and go to our daily meeting with the Sakura Particles and the Mavericks to debrief what happened the previous day.

We work for a few hours until lunch and eat at the DESY canteen. Then, if it's a regular beam day, we'll go back and do more work at the beam in our respective teams until dinner. On some days, however, we have special trips planned - like visiting the dahlia garden, or going to a Korean restaurant (the bingsu was delicious!)

As far as the experimental side of things goes... things went pretty badly on Sunday. We were trying to do different tests to align the beam center and the grating while also determining the optimal angle for our SiPMs, meaning we spent over an hour just getting our setup into the darkbox. Even then, our goniometer wasn't really working, so we spent extra time debugging that... needless to say, it wasn't a very productive day. However, we all learned a lot after debriefing with Antonios and Antoine, who ended us on a good note: Antoine told us that the ATLAS group took over 4 days to start collecting data with a setup they'd known for years. Hearing that made me a feel a little better - combined with the fact that last year's team at DESY also only started data collection on Sunday.

It's clear that organization is huge in conducting any experiment, and we all learned and grew a lot from the experience. On Monday, things went a lot better! We made a runlist beforehand and also had a huge checklist on the Central Whiteboard™, which we updated whenever we got something done. We managed to get through all 6 of our runs - a lot better than the day before!

Even though Monday was our most productive day yet at the beam, we surprisingly had a lot of downtime. While we were waiting for data to collect, we had plenty of time to analyze data from the previous run and also catch up on homework and life. We even went for a lap around DESY's campus together where all of us commented on the general state of our brains (absolutely, totally fried), and even though we were all dead tired when we left the test beam, there was a sense of accomplishment and reward that hadn't been there before.

Now that we're reaching the end of this entry, I don't have anything particularly profound to say. I just know with certainty that I'm going to miss DESY when we leave - which still doesn't feel real yet even though we're leaving in two days at the time that I'm writing this. The surreal feeling of "holy sh*t, we're in Germany" has worn off, replaced by a sense of steadiness and routine. I'm sure the DESY staff will be glad to finally get some rest - but we, or at least me, Robert, and Niranjan, want to stay here for at least a month longer!

For my lack of eloquence, here's an afterword from Mrs. Givens:

My impressions over the past 10ish days at DESY:

• How cool particle physics is... and how much there is to learn!
• Scientists are so collaborative: Antoine & Antonios gave up a lot of time to help our group. But others as well – mostly coders I think – came to assist with the project.
• This group of kids is so articulate! They discussed their project with knowledge before an international audience – never got rattled by questions.
• Real science is very different from in-class labs: it is not always easy to decide which variable to alter, and when; or what variable to hold constant: there is only a certain amount of time and no lab procedure telling you to “Do this then do this”!
• Also real science consists of staring at computer screens a lot.

BEST FIELD TRIP EVER!!!