A Summer in CERN – Chew Kang Ying, UPM

My CSSP Experience
By Chew Kang Ying

Walk us through your activities during CSSP 2019.

For the first four weeks, I was assigned to Aamir Ishard as my first supervisor, and Francesco Fallavollita. I was assigned in a Gas Electron Multiplier (GEM) group for Compact Muon Solenoid (CMS) endcap project. At the time, I was assigned to the GE 1/1 detector.

During the first week, I visited the assembly lab and quality control (QC) testing lab in Building 904. I assisted in one of the assembly processes, which is installing VFAT3 on the GEM board. Additionally, I was given materials such as a Technical Design Report to study regarding the electronic parts for GE 1/1 superchamber.

During the second week, I entered the Testbench Lab for VFAT3, accompanied by Aamir, Paola and Filipe. I learnt the process of VFAT3 testing and also categorising the VFAT3 according to their performance. Each test took an average of three minutes to complete, after which they will be rated as green (good), yellow (minimal problem), and red (serious problem). Only green VFAT3 chips will be sent to Building 904 for assembly.

During the third week, I continued to test more VFAT3. Together with Paola we finished testing Lot Number 5 for VFAT3, which contains 473 VFAT3 chips. At the same time, I was learning the parameters for VFAT3 testbench QC testing. Here, I was taught to set the limits for ENC and threshold. I also learned how to updates the testing program, how to download the data from the server and how to display data out from server.

I also attended a presentation for summer students in Building 904 to listen to Paola’s presentation. During the fourth week (Paola’s last week at CERN), she conveyed her knowledge during her one and a half months working in VFAT3 testbench to me. Together, we also opened Lot Number 6 with 404 VFAT3 chips, and I stayed up until 10:00 pm some nights to make up for the time I spent visiting CMS, the ATLAS control room and the synchrocyclotron.

I completed the testing of Lot 6 in two days, and the next week we started the largest lot: Lot 7 which has 644 VFAT3. My supervisor promised that after I complete this lot, we will take a two-week break, during which he would teach me detailed testing of yellow and red problematic chips, for which I was excited.

Throughout the four weeks, we have lectures daily from 9:15 am to 12:30 pm, ranging from basic introductory courses to very detailed and advanced courses, e.g. astrophysics, accelerator physics, cosmology, detector physics, electronic and data acquisition, LCH hadron experimental physics, superconductor physics, data representation, heavy ions collision, particle physics, quantum field theory standard model, beyond standard model and string theory.

While at CSSP, I had the opportunity to visit the Anti-proton Decelerator, and Data Centre on 18 July, ATLAS control room and synchrocyclotron (23 July) and the CMS detector and cavern (24 July).

The Anti-proton Decelerator is a project where they study anti-matter; experiments include Gravitational Behaviour of Antihydrogen at Rest (GBAR) to test the gravitation effects on Anti-matter and Atomic Spectroscopy and Collision Using Slow Antiproton (ASACUSA) to measure the properties of Antihydrogen spectrum of light when positron is excited.

The CERN Data Centre stores 50 petabytes of data in magnetic tapes annually during LHC runs as it is durable, inexpensive and compact. They are cooled to maintain the efficiency and utilises a separate power supply. Meanwhile, the ATLAS control room is where the ATLAS experiment monitoring is carried out. During a LHC run, workers have to work in shifts and experts are always available on an on-call basis.

Besides that, Synchrocyclotron is CERN’s first accelerator, which started operating in 1957. This machine helped to revolutionise nuclear physics in the world. It was closed down after 33 years of remarkable service, after the proton synchrotron was created to replace it. CMS stands for Compact Muons Solenoid, which is a general-purpose detector for LHC experiments. Malaysia is one of the contributors and is closely affiliated with the project.

How did you spend your free time outside of work?

I enjoyed social moments during downtime at CERN; having drinks at the Charly Pub as well as being invited to a crepe-making party, pizza-making party and a Spanish movie session. I often make dinner alongside other participants like Anne (French), Lisa (Russian) and Mario (Spanish).

On 3 July, all summer school students were invited for a student mixer hosted by the committees of CSSP, where we had the opportunity to interact with each other. On 6 July, I went to visit Geneva. I visited the UN Building and the Peter Pallek museum. On 7 July, I went to Chamonix, and went up to L’Aiguille du Midi. On 11 July, I joined a workshop on how to build up a cloud chamber. From 13 to 14 July, I went to Amsterdam, visited the Van Gogh museum, Stedelijk museum, Rijkmuseum and Rembrandthuis house. On 17 July, I visited the International Geneva Toastmasters Club, where leadership and public speaking skills are trained. From 20 to 21 July, I went to Vienna, visited the houses of Beethoven, Haydn, Schubert, Mozart, Johann, as well as Albertina to view paintings by Picasso. From 27 to 28 July, I joined Webfest, which is a first-hand design programme for application or website, where we created an application named CERN Learn, a platform to get experts and students to meet each other casually for a meal or coffee and talk about interesting topics or collaborations. CERN Learn earned us the third place in Webfest.

Upon completion of CSSP, have you found your “niche” in particle physics that you would like to pursue?

Throughout four weeks of lectures, I have found that I am really interested in theoretical physics. Lectures like Quantum Field Theory, Particle Physics, Standard Models, and Beyond Standard Model really intrigued me. I also spoke to a several theoretical physicists to to find out the inner workings of the theoretical physicist’s mind.

How will the stint at CERN impact your current studies, and subsequent academic pursuits (Masters/PhD)?

One of the biggest challenges at CERN that I faced was data processing speed. CERN searches for more new particles by observing new proposed interactions of unknown particles with existing particles in standard models. Two issues arise from this:

1. Currently, the highest estimated energy for the Large Hadron Collider (LHC) is 7 TeV and a head-on collision will go up to 14 TeV. They are proposing to search for particles in the ranges above 20 TeV, which will lead to future FCC project being proposed, pending approval. Surely, they will need a lot of engineers, computer scientist, and most importantly experimental physicist.
2. Another issue is the cross section for such interaction as predicted by the standard model will be a few orders of magnitude lower than Higgs interaction. In order to obtain data with significant level of 5 sigma, they need to increase the luminosity which lead to more collisions, but this will be very taxing for current computers to bear the data intake. CERN proposed using quantum computers to solve this.

I am very interested to find out the lower bound of time complexity of quantum computer as opposed to classical computers, therefore CERN’s quantum computer research could really help me in mine. Besides that, it also opens up opportunity for me to pursue theoretical particle physics.

Thoughts

Four weeks spent at CSSP has been an eye-opener for me. The lectures I attended informed me of what happens behind each discovery; a high-level of expertise is required for projects to function and to obtain the data that we really want, while simultaneously minimising cost and damage to both the structures and environment.

In addition, I realised that beside the important scientific discoveries made here, there is another significant workforce helping out to achieving it: administrative workers, QA and QC workers, translators, educators and more. Not only that, the GEM team in which I was working allowed me to experience the CERN work environment, meeting expectations and carrying out responsibilities. I also witnessed how their meetings, and how the smallest issues were taken very seriously.

During the Webfest programme, I experienced the working environment of fellow programmers and how people of different nationalities work together: we had two Polish, one German, one Indian, one French, one Romanian and of course one Malaysian in a team.

On the social aspect, I experienced cultural exchange during the crepe party, pizza party and Spanish movie session, notably with the French and the Spanish. I too found that I have adapted to the weather in Europe, their food and their culture.

Appendix:

Project

CERN visits

Fun time after work with friends:

Travel: