Jack Plantz: Particle Physics, Week Four

This has been a whirlwind week. I got my code to work, got to help with the experiment on the beam, and over the weekend I went to the Outside Lands music festival in San Francisco.

Most of the work this week involved preparing for the experiment on Friday. I ran more simulations and re-wrote my python analysis code to do an average of a bunch of random seeds of the electron beam before graphing the result. This makes the graphs more representative of the actual spectrum the beam would have, and makes it easier to compare the performance of different magnet lattices, such as SASE and iSASE.

I also helped Juhao and Kun write up a procedure that we would follow for the experiment so that we would keep focused during the shift. Experimental time with the beam is very hard to get. Even with the beam running 24/7, SLAC can only accept 1 in 4 experiment proposals. So we happened to get scheduled for our experiment from 11pm to 5am and needed to take full advantage of the time. Every step of what we needed to do was written out and planned so that we would have enough time to finish, and so that we could still remember what to do at 3am.

When it was time for the actual experiment, Juhao gave me a ride to the MCC (Main Control Center). Every wall is covered in computer screens displaying data describing every characteristic about the beam. I had to have Claudio, another member of Juhao’s team, explain what everything meant and which ones were important. Also, whenever we changed something about the beam, the computer would read it out in a Lord of the Rings voice. Somebody programed it in to keep them awake during late shifts and it just stayed in the computer. So every once in a while it would say something like “K-parameter adjusted, my precious” and I’d start laughing.

Main Control Center. The most useful graph is the big jagged pink one. If it’s there it means the laser is running.

It took a lot longer than we planned on to get the beam to the conditions we needed to run the experiment. Juhao and Kun wanted the beam pulses to be short (30 femtoseconds), have a low current and have a nice phase distribution that wasn’t skewed or anything weird. But when the beam operator would try to change the beam to make it fit these conditions, the beam would stop lasing and stop emitting X-rays. It took hours of messing with different parameters to try and get the beam to a usable state. We eventually settled for something less than ideal but we had to run the experiment and start taking data. We got the beam to start recording data at around 2:30am, then Juhao and I left and Kun and Claudio finished up the night.

Trying to get the laser to the right conditions to start the experiment.

My first selfie on this blog

I slept in late the next day and went out to breakfast with the Gershenbergs. Marcus had a VIP wristband to Outside Lands that his cousin, who works for a record company, gave him for free. Outside Lands is a huge music festival in San Fransisco, like Coachella. He went for the first day, Friday, but he said he didn’t have any fun because he didn’t know anyone there and asked if I wanted the wristband. I couldn’t believe it! I immediately said yes and started figuring out a way to get there. I rode my bike to the Menlo Park CalTrain station and got there just as the train was pulling into the station and rode it all the way into San Fran. Then I rode across the city to Golden Gate park, only getting lost like four times, and I was there.

I’ve never seen so many people in one place in my entire life. I found out later that there were 210,000 people in the festival each day. I was like if you took Telluride Bluegrass festival and tripled the number of people there, then had three festivals like that going on right next to each other. There were four stages and vendor tents everywhere.
I saw so many great artists, like The Black Keys, ODESZA, Milky Chance, Slightly Stoopid, Cold War Kids and so many others. I also ate a burger with two glazed donuts as buns and had some chocolate covered bacon for dessert (because it’s not that often you get opportunities like that).

It was a little bit difficult getting back to the train station afterwards because my phone ran out of batteries so I had no map. But I found a super long train of bikes that was headed out of the concert all the way to the train station so I just followed them and made it back home. I went both Saturday and Sunday. Sunday night I missed the last train home by about 30 seconds. I saw the train driving away as I got into the station and ended up having to Uber a ride home.

Overall, I had a great week both working and playing. I can’t believe how fast this internship is flying by.

Lost in the crowd

Black Keys

Slightly Stoopid

Giant burger balloon getting tossed around by the crowd. Eventually it got popped when a guy tried to take a bite out of it.