by Arturo Tauro & Panos Charitos. Published: 14 September 2014

After a long shutdown period, the PS has finally been put into operation and ALICE is making extensive use of it in the East Area. The main goal of these test beams is to qualify new protoypes, calibrate the detectors and to check its electronics, in order to develop  the whole acquisition chain. People are working very hard day and night in order to profit at maximum of the 7 days usually allocated to them for the test. This is the case of the FIT/T0-plus group, who has recently installed, in the T10 line, a prototype of the main trigger detector, exploiting the Cherenkov effect,  for the ALICE upgrade in LS2. Taking advantage of the restart, the FIT team has successfully tested new prototypes of T0+ and V0+ detector modules. Moreover, the same 6 GeV/c beam line is presently used to test the new pALPIDEfs sensor, a possible candidate for the ITS upgrade in LS2.

Participants of the T0+ test at the T10 beam line in the East Area. Standing from the left: Maciej Slupecki, Oleg Karavich, Vladimir Kaplin, Arseni Shabanov, Dmitri Serebryakov, Alla Maevska, Yuri Melikyan, Artem Konevskih, Tatiana Karavicheva, Andrey Reshetin,  and Wladyslaw Trzaska

The pALPIDEfs chip presently under test is the first full scale version prototype (3 x 1.5 cm2 , ~half a million pixels, developed in the Tower Jazz MAPS technology) for the new ALICE ITS. It is developed by CERN, INFN (Italy), Wuhan (China), Yonsei (South Corea), NIKHEF (Nedeerlands).  

Set up for the test of ALICE's new pALPIDEfs chip in the T10 beam line

These two groups are perfectly capable of sharing the beam, and will soon become three, when the FIT/V0-plus will arrive next week. This is a typical example of good collaboration! But they are only the first of several groups who are alternating every week in both the T9 and T10 lines. After the summer it will be the time of TOF, PHOS, HMPID and FOCal, with the ALICE ITS also present most of the time .

The beam requests need to be collected (this is done months in advance) and the proper support arranged from CERN (e.g. transport, tools, patrol courses, services, etc). People are here only for a short time, and often are not very familiar with the (always evolving) CERN procedures. So there is no time for improvisation: every hour is precious and one has to get the best support in order to make efficient use of the time at CERN.

There is also the safety aspect which is very important: each time before taking beam an inspection is organised with the CERN safety people to make sure there is no danger related to the installation and that everything can be carried out without any risk. In addition, the many ALICE users are represented in the weekly PS/SPS coordination meetings, making sure the information is properly distributed to/from the different groups.

The SPS will restart only in fall, and ALICE is very keen in taking beam in the North Area. There things will become more complex, because of the huge number of people willing to participate in these test beams. So one of the challenges is to obtain a slot, and we are very happy that the ITS, TPC and FOcal have already secured their beam time for this year!