Hackathon 8th-11th March 2020


While detectors like LIGO and Virgo have proven their success, we want to do even better in the future! The current detectors are not perfect: they are partly limited by their design, and partly by issues like controls challenges that were not forseen before they were built. 

The ultimate goal of this Hackathon is for you to adapt an Advanced LIGO-like interferometer model to meet a new set of requirements. Designing a new detector is an immensely complex challenge! A list of key considerations is provided to help guide your efforts.

The Hackathon will begin with some shorter tasks that you should work through sequentially, followed by the main project. You should use what you learn in these tasks, as well as what we covered during the Workshop and Mentoring programs, to inform decisions you make in the final project.


Unlike the workshop, your time will mostly spent working independently in your groups, starting from blank jupyter notebooks. On day 1 you will be given 2 tasks that are more guided and help build your intuition for the project portion. Days 2, 3 and some of 4 are up to you: use them to carry out your chosen project task to the best of your team’s ability! On the final day you will present your results to a team of judges. Some will be present in person while others will join remotely (via Zoom or similar).

TimeActivity8th Mar9th Mar10th Mar11th Mar
10:00-11:00Session 1IntroductionIntroduction,
Project Selection
11:30-13:00Session 2Task 1ProjectsProjectsPreparing
14:30-17:30Session 3Task 1/
Task 2
17:30-18.00Tea + snacks
18:00-20:00Session 4Task 2ProjectsProjectsPresentations

Help and Support

You will notice that the mentors from the workshop aren’t here this time! By now you should hopefully have the skills to resolve simple issues among yourselves, by checking the Syntax Guide, Cheatsheet, and Finesse 2.0 Manual. However, your mentors are available to provide remote support for technical issues, should you find yourselves stuck.

Since this is a competition, we want to ensure fairness among all teams. Therefore, if you have a question, please post it to the sandbox blog so that the mentor’s answers are equally available to everyone (and we don’t get the same question multiple times!).

Bear in mind that since the mentors are based in different time zones, you may need to wait for a response.

Presentations & Judging

The Hackathon winners will be assessed by 4 judges, who will listen to a presentation of your design on the final afternoon. The judges will all have experience with gravitational waves, but will not all be Finesse experts. Therefore you should make efforts to explain the physics behind your model and what it implies, as well as giving an indication of how you used Finesse to achieve your results.

Your presentation should last approximately 20 minutes, followed by 10 minutes for questions. All team members should contribute equally. Generally we recommend no more than one slide per minute; use this to gauge and prioretise what results you share.

Judging Criteria

  • Understanding of the physics involved in the simulation (including comprehension and critical evaluation of your results)
  • understanding and competence in using Finesse / Pykat
  • clarity of presentation
  • bonus: exploration ‘above and beyond’ the Hackathon problem, which deserves extra merit at the judges discretion

Results should be announced by the 15th of March.

Presentation timetable

2:30Team 1
3:00Team 2
3:30Team 3
4:00Team 4
6:00Team 5
6:30Team 6
7:00Collation of results

Please upload the presentation materials from your project to this website by creating a new post titled Team X Results. Your slides, in PDF format, should be uploaded no later than 1pm on Wednesday.

Before the end of the day on Wednesday, please also upload a zip folder to the same post, containing:

  • a .kat file for your group’s final detector design
  • Jupyter notebooks and any related files to produce all plots from your presentation

Hackathon Materials

Day 1 tasks

Today you will study a 3-mirror linear coupled cavity. This will help you to revise what you have leaned previously about error signals and control, and Gaussian optics, in a more complex optical configuration that is closer to current gravitational wave detector configurations. Follow the steps provided in the attached pdf, starting with an empty Jupyter notebook.

Project descriptions

Your project is to develop a new detector design. There is a choice of two projects: read through both and decide as a team which design you would like to attempt. While these designs will involve different approaches along the way, all teams will produce some common outputs, such as a sensitivity curve.

The pdf below provides an overview of both projects, but is not a step-by-step guide: that’s the challenge of the Hackathon! The file simplerLIGOm4.kat is a (slightly) simplified version of the advanced LIGO design file you saw briefly at the end of the Workshop. You should use this as a starting point / reference to compare to your new design.


Links to


# Date User Information
396 4 years ago Anna Green (current)
387 4 years ago Anna Green
386 4 years ago Anna Green
383 4 years ago Anna Green
353 4 years ago Philip Jones
1 2 3 4