by Panos Charitos. Published: 05 December 2012

ALICE MATTERS interviewed Jacobus van Hoorne from Austria who is currently working on the evaluation of monolithic pixel detectors; a new technology that was developed at CERN as part of the ITS Upgrade efforts...

A.M. What did you study before deciding to pursue your PhD with ALICE?

I studied Technical Physics at the Technical University of Vienna, where I attained both my Bachelor and Master degree. I decided to study physics due to the same reason that I think most other students do as well –a strong interest in understanding and investigating natural phenomena and technological advancements in depth.

The topic of my Bachelor’s thesis was related to the nTOF facility. This is how I came in contact with CERN for the first time.

From that moment my interests were more and more drawn to the ongoing projects here at CERN and particularly to detector physics. That's how I started contributing to some projects of the Austrian Institute for High Energy Physics (HEPHY) related to the CMS and the BelleII detector.

In 2010 I had the chance to work at CERN as one of the few participants of the HEPHY@CERN program and immediately was very impressed by the outstanding working atmosphere in this international environment.

During a stay of nine weeks in the summer I joined the ALICE VHMPID group in R&D on CsI-TTGEM based photodetectors. From this work I got my first great insights into the progress of the photodetectors based on the GEM technology and the development process of detectors in general.

However, through these insights I became more motivated and I decided to apply for the CERN Technical Student Program. In the framework of this program I was selected by the CERN Beam Loss section to work on the R&D for a beam loss monitor for CLIC based on Cherenkov fibers.

Since September 2012 I have been working on my PhD within the ALICE ITS upgrade team, where I am currently evaluating prototype structures for monolithic pixel detectors designed in a 180nm CMOS process both in the lab and the testbeam.

In the longer term I want to study the charge collection properties of monolithic pixel detector prototypes in detail, with a special emphasis on the performance after irradiation.

A.M. How did you decide to work in the ITS Upgrade? When did you first hear about ALICE ITS?

I heard about the ALICE ITS during my stay as a HEPHY@CERN summer student. Since I worked on an ALICE project I was very interested in all the ALICE subdetectors and how they complement each other. Perhaps needles to say that the Inner Tracking System of ALICE is an important subdetector and it can't be simply overlooked.

Later, during my application for the CERN Doctoral Student Program I came in contact with members of the ALICE collaboration who were responsible for important parts of the detector upgrade. After several discussions I was convinced that the ITS upgrade is a very interesting and promising project and I decided to move on and pursue my PhD research on it.

A.M. How familiar have you been with the study of the QGP and the physics explored by ALICE?

Since I had worked for an ALICE project before I was already familiar with the physics and physics motivation of ALICE. Furthermore, in the framework of my Master’s studies I also attended several courses on particle physics and in those we also discussed QCD and QGP, as well as the details of the ALICE detector in general.

However, for my current job, which can roughly be described by R&D on monolithic pixel detectors, I do not think it is particularly necessary to fully understand the physics program of ALICE. Of course it is always good to know how the requirements on our final detector are derived, but for my work it is more important to understand the physics and electronics processes which contribute to the signal generation and determine the behaviour of the detector due to a traversing or absorbed particle. Therefore at the moment I try to focus on semiconductor physics and to absolutely understand the analogue and digital electronics circuits which appear in the great set of prototypes I am currently evaluating.

Jacobus van Hoorne a PhD in his lab, testing different technologies of pixel detectors for the upgraded ITS.

A.M. How long are you staying at CERN?

I will be staying at CERN for the complete period of my PhD studies which means that I will be here for the next three years.

A.M. Your future plans? What is your aim during the period that you will be spending here? Personal career plans?

I really like working on particle detector physics and R&D and I would like to stay and keep working in this field. However, at the moment I do not have any specific personal career plans, since I can't actually foresee how my life will evolve over the next three years both in terms of professional and private aspects.

Therefore, up to now my approach has always been to work as hard as possible for the success of the projects in which I am involved. At the same time I am trying to learn as much as I can and benefit from each project. In this way I hope to maximize the set of options when I finish my PhD and before start looking for a new position.