Week #160

17 – 20 February

Monday is Rose Monday and my workplace is heavily influenced by carnival. Therefore, we get the day off. I use the day (and the weekend before) to get some writing done.

Tuesday onwards I work on another extension for our simulation framework. I’m using an ideal track finding algorithm which basically finds tracks from charged particles by taking a hit in a detector and looking up the simulated truth information. Of course, this only works in simulation and won’t in the real detector, but for now this is fine. I have to do it this way because the track finding algorithms capable for my channel are not ready yet.

Ok, ideal track finding. This is working quite fine, too good actually. Only if there is just one point, it will find the appropriate track — which in real life wouldn’t be possible. You need at least three points to fit a circle and two for a straight line. In order to make this a bit more realistic, I want to filter out those tracks which left too few hitpoints in the detector to realistically reconstruct a track.

I want to make it properly, thus it takes me some time to figure out where exactly I should insert this task and how it should be written. I make good progress, but can’t finish because of …

We finally got an LVS clean desing.

We finally got an LVS clean desing.

PASTA: After trying to solve the assign issue from last week and not finding a suitable solution in time, I decide to remove the related pins. They were not doing anything anyways, so logically there is no change1.
After solving this, we finally got an LVS (layout vs. schematics) clean design, meaning that the design on the metal level is the same as the logical input. Puh, that was quite a ride.

  1. They still have been in the design because it would have made it much easier to reactivate that in case we decide to use it. []

Week #159

9 – 13 February

In this week, I finish the event filter I started working on last week. I do a quick test to see if it produces what I think it does and am quite satisfied with the result. The next thing to do would be to produce a lot of data on the computing cluster, but before doing that, I want to include something else.

So far, I had the hit counting done separately, leading to a file which just gave me the number of hits associated with a particle and detector. To do some more elaborate analysis, I want to crosscheck the hit count of each event and apply some cuts on that. The afore-mentioned approach doesn’t allow that since the assignment of events is quite difficult. My plan is to write a task which is called during event simulation which collects the hit count information and stores it along with the other information.

I start with that, but it is a bit difficult to get into. On Thursday I have a task running which is initialized and stores data, but doesn’t do anything yet. I’ll continue next week on that. Friday and the weekend I stay at home to write.

PASTA: During the week, a quite severe issue appeared. Due to some assign statements in the schematics, the checks detect a short-circuit and consequently fail. This is bad for submission, so we (me and the guys in Torino) try to figure out a way on how to solve this. Along the way we realize some other issues, part of which we are able to solve, part of which need more time. Let’s see what next week brings.


Week #158

2 – 6 February

The week begins with a meeting with the professor. Discuss last results and next steps. I have quite some plots to show since I found this bug with the wrong particle. The main thing we decide on is related to the event filtering method1: keep it! So I start adapting the concept to the full simulation chain.

There it is crucial to do the filtering early because full event processing takes a lot of time. Luckily, some colleague already extended our simulation framework to enable such things but of course not with the filter I have in mind. So I start reading into the filter mechanism and how to include my own.

PASTA: In the meantime, some connection problems occurred with the GCTRL. I try to fix it, compile a new version, see other problems occurring, fix them, compile again, … Args. Someday, this will be finished.

  1. As described in the last post: generate homogeneously and then remove some events based on a probability distribution. []

Week #157

26 – 30 January

I generate more hit count plots and at the end I have a display which I like. In one plot I display the amount of hits for different particle species and do that for all four particle detectors.

After finishing this, I remember another thing I wanted to do: use another event generation model. That basically means, how the particles are produced in the initial reaction. By default, the generator assumes a homogeneous distribution, also called phase space distribution1. But reality shapes an asymmetry because some quarks are not converted and thus carry their initial momentum.
Anyhow, after discussing with some more experienced people in this field than me we figure out that this would be too much to implement on a realistic level. So we opt for another method: generate a homogeneous distribution and randomly exclude some events with a certain probability for a given value. This is relatively easy when just looking at the event generator because this is quite fast. So we don’t have a huge overhead of producing, let’s say, twice the amount of data.

While discussing, we notice something: I used a wrong particle in my initial state. This led to strange results. Even though I first have to define the particle, the fix is relatively easy.

On Thursday I take a day off to deal with some organizational stuff at home.

  1. Because it covers the full phase space homogeneously. []

Week #156

19 – 23 January

I finish the program counting the hits per tracking detector and send this to the computing cluster to simulate 100 000 events. On a single machine this would take a week or so, on the cluster only half a day. Quite nice speed-up.

While this is running, I make some detail corrections on the life time plots, mainly to have something that can be properly used and is not just something for a quick discussion.

On Wednesday my simulation is finished and I start analyzing the data. In the course of the next days I think of several ways on how to display the amount of hits in a good way.

PASTA: The idea we had last week (leave the top are completely empty) wasn’t such a good idea after all because this violated some design rules. Therefore, I went back to the concept I had before.


Talk: Neutrino Sources

Subtitle: … and some basic detection principles
Slides: 34
Duration: ~ 55 Minutes

Date: 13 January 2015
Occasion: IKP PhD seminar
Location: IKP, FZ Jülich
Audience: Other PhD students, mostly IKP-1

I repeat some slides from last time to remember people of what we already talked about. The rest is an overview of different sources with their properties. It went quite well, from what I can tell.

View on Speaker Deck | Download PDF (4.7 MB)


Talk: Stars, Supernovae, and Neutrinos

Disclaimer: I forgot to upload this when it was due, thus the delay.

Subtitle: A brief introduction into the stars of astrophysics.
Slides: 16
Duration: ~ 45 Minutes

Date: 28 August 2014
Occasion: IKP PhD seminar
Location: IKP, FZ Jülich
Audience: Other PhD students, mostly IKP-1

My turn in the weekly PhD seminar. I wanted to focus on astrophysical neutrinos and started with supernovae. The topic grew a bit, so in the end I mainly talked about supernovae and postponed the more general neutrino talk to the next time.

Generally it went fine. Some explanations were a bit half-baked because I didn’t rehearse this talk. But the atmosphere is quite relaxed and invites discussions, so it’s fine.

View on Speaker Deck | Download PDF (2.6 MB)


Week #155

12 – 16 January

The week starts with me preparing a talk in our PhD seminar for Tuesday morning, this time focusing on neutrino sources. Surprisingly I’m quite efficient with that, considering that I get a ~50 minutes seminar talk together in only 1,5 days.

On Wednesday we have the bi-weekly meeting with our professor. The main tasks I got from last time were already finished and the next step of using the full simulation is still ongoing (mainly because I have to understand how the concept of the framework is set up). Towards the end of the week I figure out where I have to insert my part of the code. And also how to use the computing cluster to generate a significant number of data.

Until Friday I’ve prepared scripts to generate data and analyze the number of hits per sub detector, they just need some final touch. But this is work for next week.

PASTA stuff is also going on. The developers in Torino had the idea to really leave the space on top of the GCTRL empty (not just without active cells), so I figure out how to do that. Unfortunately, all these things are trial and error based on a compilation that takes 4-5 hours. So the progress is really slow 🙁


Week #154

5 – 9 January

Happy new year! The last of my PhD. And probably also the most stressful.

Now that I’m back in the office with colleagues around who I can bug for questions, I can start with properly analyzing the data I produced before Christmas. The tasks I got from my last meeting are done relatively quickly, so I continue to have a look on using the detector simulation.

The examples run relatively fast and we have a first look at the outcoming data. As expected my decay channel is a bit too advanced for the current status of reconstruction, so I have to switch to ideal tracking. This means the scripts take advantage of the generator information1, obviously something which won’t be available in the final detector.

It is a bit hard to get familiar with the concept the framework uses, so I can’t finish with that this week.

As always, I work on the PASTA design in the meantime. Still figuring out details on the connection for DAC configuration.

  1. like which particle left this trace in the sensor []

Week #153 – Vacation

29 December – 2 January

It is the time between years. I’m on a short vacation with friends. I try to find some time to write but am not that successful. But at least greater than zero.

I also get my scripts running which count the written words in .tex files and puts it into a database. Based on this, I’d like to get some statistical analysis on when I write and how much I get done on average. Let’s see when I’ll find the time for that, at least the data taking has started.