As I write these lines, I have been on night shift for one hour. Hopefully this time, we are in a store and we can take a physics run – it wasn’t the case over the three previous days because of some issues in the TeVatron. But we have to be prepared for this all night of shift, which is just the fourth of seven days.
11:00 p.m. is time to wake up for me. You have to follow a perfect schedule to avoid health problems when you are working during the night. So you often plan to sleep since 4:00pm to 11:00pm and have a great night/afternoon of sleep. For this, I have my own tricks to fall asleep pretty quickly.
First, I had my dinner during the lunch period, that is to say at 12:00 a.m. typically. It’s a good way, before going to sleep, to tell your body that you expect to sleep in the next hours. Then, I take a shower to cool my body, wash my teeth like a good boy and go to sleep. If you sleep well, you are pretty not tired when you wake up. Then, take a breakfast with bread, cereal, milk and orange juice (again, to trick your body and take some sugars to be efficient during the shift) – of course, at the beginning, it is pretty weird to do that stuff at 11:00 p.m. but anyway, you have to be at work at midnight to begin you shift!
My colleague/friend of my french lab is there so I can avoid taking the bike at midnight to go to work (which is very good, I would like to thank him with this post); then you arrive in the DZero control room and speak with the previous shifter to be aware of all the previous issues encountered and how to fix them if you are lucky. You are waiting for the other new shifters to be there i.e. the Track shifter (for the tracker system part of the detector), the CalMuo shifter (for the calorimeter and muon system parts) and the Captain, who leads all of us. As a DAQ shifter, I am responsible of recording data in the computers to let the worldwide DZero people working on these data. As you can easily understand, it is better not to make errors, especially now, one month before the TeVatron ends!
During the first hour of your shift, you need to make a walkthrough, that is to say, going to see how the servers of computer farms are working and if there is no error during data taking and processing. Usually, there is no problem, or if there is some, you already know it by watching of the nine computer screens you have in front of you.
Each screen has a special duty, necessary for you to know what has actually happened, and most of the time, how to solve the encountered issues. For my job, I have to be sure that the events are well recorded after bypassing though a lot of triggers, whose are responsible of taking only interesting events for our further analysis. There are actually three different levels L1,L2 and L3. The L1 trigger has to be the fastest to make a decision in microseconds, then to send data to L2 and finally to L3 (before recording tapes). The data recorded will be used by the collaboration to make plots you already know.
Then, you can easily expect to make other interesting operations as the beginning of a new store, which consists of reinitializing the computer framework to be able to record data on tapes for several runs. These runs will be used after that by other people to filter all of this information. Of course, there are some troubles sometimes you have to fix (especially when you have a huge responsibility).
I always remember my first day of shift at the end of June when it was such a mess – I was frightened and I can not do anything, waiting for the captain instructions. Most of the time, you have to keep cool, to talk to other shifters and see if the issue already happened in the past.
This is now my last time on shift. I am not working at DZero since a long time but I can say that it is quite sad to think that, in a month, all of that will be over. All of these discussions, encountered problems, laughs sometimes and learning science were wonderful experiences for me. I would like to thank again my PhD advisor which was responsible of this opportunity and, of course, the Fermilab DZero team.
Thanks to Fermi National Accelerator Laboratory, thanks to the great DZero team and thanks to you, readers of this post.