Published: 29 July 2015

My name is Taku Gunji, from the Centre for Nuclear Study, University of Tokyo, and it is a great pleasure for me to be one of the period run coordinators in 2015.

I am having an exciting time in the ARC and I feel like thanking all the subsystem experts and the shifters while I owe special thanks to the Run Coordinator, Federico Ronchetti, and Dhevan Raja Gangadharan, June’s PRC.

As a Period Run Coordinator I have gained a lot of experience and knowledge about the core of the ALICE experiment (detector subsystems, DAQ, Trigger, DCS, DQM, offline, HLT, LHC_IF, backgrounds) while I had the chance to learn many things about the accelerator basics of the LHC (many acceleration sequences, machine performances, beam instabilities, losses) as we had to face some problems during beam operations handled in a very professional manner by the machine operators. 

The major ALICE activities during July were to take muon rare triggered data during the 50 ns high-intensity ramp-up campaign. The LHC increased the number of bunches from 3 to 764 (up to 36 colliding bunches in ALICE).

Typical operational conditions in ALICE were 300-500 kHz V0 interaction rates and mu~1 (average number of collisions per bunch crossing). In parallel with muon rare trigger data taking, the central barrel detectors ran in the same or in a different physics partition, in order to understand the detector performances under high intensity and high pileup conditions, an important aspect for the upcoming top energy heavy-ion collisions. 

Unfortunately, our goal of integrated luminosity wasn’t accomplished due to the struggles of the LHC to deliver collisions at high beam intensities.

All in all it has been very exciting for me to witness the ALICE performance under such high rates. As this was my first time as a PRC I am not sure if I fully met the expectations of my role but I was very happy to coordinate activities with the system experts and detector experts to improve the operation of ALICE during this period. 

Sometimes I spent the whole night in the ARC often feeling exhausted. Perhaps surprisingly the stable beams always refreshed me completely and I was able to concentrate 100% in the ALICE operation with a lot of fun.

My PRC role is going to finish soon and will be handed over to Michal Broz, the next PRC (who is getting acquainted with the job and to whom I wish a very successful period).

However I will continue working for ALICE and specially my involvement that dates back to 2002, which was the first year of my master course in the University of Tokyo. In the past I participated in the TRD project and studied the electron identification performance of a TRD prototype in a test beam at the CERN PS (Thanks to my supervisor, Prof. Hideki Hamagaki, and TRD project leader, Prof. Johanna Stachel, while I also feel grateful to Dr. Anton Andronic and Dr. Chilo Garabatos).

I resumed my activities in ALICE in 2007. I started working on TRD again and joined the FoCAL project. In 2010, based on our group’s experience of GEM detector R&D, we joined the GEM TPC Upgrade. 

Over these years, I have also participated in the TPC RCU2 project; I have been mainly involved in the data analysis of the low mass dielectron in pp, p-Pb, and Pb-Pb. This is one of the challenging analyses due to its poor signal to noise ratio. Huge efforts are being made with the PAG members and some results will come in the near future. 

Last but not least, I really had a good time and experience in the ARC and I really appreciate all your cooperation on the operation of ALICE. Let’s continue our journey for discovery.