by Polly Bennett. Published: 25 November 2011

Since 2008 two awards are given once a year for the most outstanding PhD thesis by members of the ALICE Collaboration in the field of physics and instrumentation, respectively. The awards celebrate the excellence of young researchers at ALICE and the importance of their work in the physics world. The selection is made by a small committee of three members, one member of the Collaboration Board, one member from the Editorial Board and one member from the Management Board. The current members are Peter Braun-Munzinger, Bruno Ghidini and Paul Kuijer.

Here the 2011 student winners summarise their projects and reflect on the process.

Maria Nicassio (physics)

‘Study of global observables in p-p and A-A collisions with ALICE at LHC’

I wrote my PhD thesis at the end of 2009 while I was at CERN, having been granted a one-year fellowship from INFN to work full time there. My thesis was mainly about the work done in the proton-proton First Physics Task Force, the group whose goal was to prepare the first publications on proton-proton data. This experience during the last year of my PhD was really hard but also extremely motivating. I remember the day the first collisions came after a long wait: more than one year working day after day cheek by jowl. That day I could not toast with my colleagues since I had to finish my thesis in less than one month but it was a great emotion anyway: we finally had data. After my PhD I got a post-doc in Bari and since then I have gone through other exciting and invaluable experiences. A few weeks ago I was really delighted to hear that I was awarded for my thesis, as it all seemed a long time ago.

Max Brice

From left: Maria Nicassio, Bruno Ghidini, Stefan Rossegger, Peter Braun-Munzinger

Stefan Rossegger (instrumentation)

‘Simulation and Calibration of the ALICE TPC including innovative Space Charge Calculations’

Getting this award is a big surprise since I finished my thesis almost 2 years ago. Finishing was a relief after a very stressful time preparing and actually writing. I am very grateful and happy to receive this award and it has given me the confidence that my work is considered to be useful.

My doctoral thesis covers the simulation and calibration of the ALICE Time Projection Chamber under extreme high-multiplicity conditions (heavy ion collisions). Besides the differentiation between static and dynamic effects which influence the detector performance, I developed an analytical approach for the handling of field distortions due to the accumulation of ionic charges during high multiplicity events. In the process, I developed novel analytical solutions using e.g. Modified Bessel function of imaginary (and non-discrete) order to allow fast and accurate (analytical) calculations of field distortions due to any arbitrary 3-dim. space charge distribution within a TPC. This approach finally permits a nearly instant but still precise simulation of additional space point distortions due to field fluctuations in high multiplicity events such as Pb-Pb collisions.