ELI NUCLEAR PHYSICS WORKSHOP
Bucharest, 1-2 February, 2010
CONCLUSIONS SUMMARY
During the closing session of the workshop, chaired by Professors Toshiki Tajima and Nicolae Victor Zamfir, a summary was done of the discussions and proposals in the other sessions. Several elements were clarified in view of setting immediate directions of action to observe the deadlines decided during the S.C. meetings in Prague (October 1st, 2009) and Bucharest (January 14th, 2010).
The Chairmen started with general statements.
Victor Zamfir: “My hopes that we will get a lot of help from this workshop were fulfilled. We learned a lot from the talks and also from the discussions - sometimes very hot discussions. We got a consensus I think. I repeat myself but I have to say that ELI is one of the most exciting investments in infrastructures in Europe and, with all my modesty –as a nuclear physicist, not a laser physicist- that the NP pillar is the most challenging and the most rewarding pillar.”
Toshiki Tajima:“I particularly enjoyed this Workshop. I felt the energy flowing from you, the enthusiasm” Concerning the Bucharest pillar, he added that “if we don’t have this(gamma beamcapability)we’ll have to compete with other centers, Rutherford for instance, that have a 10 PW coming, or Darmstadt, who are doing a lot of experimental work in NP with accelerator (and laser). And there are other Labs too. Well, competition is not bad, but if we do here what we are discussing, then there will be no competition and everything you will be doing will be brand new and we shall be at the top of the hill.”
Zamfir added that “It was a consensus that a high fluxgamma sourcewill stronglyenhance the facility by a lot and there could be a connection between this strong, very brilliant gamma source and the petawatt laser. We heard a lot of arguments these two days. Mrs Aleonard very well presented the part of the NP as a tool for diagnosis. During the discussions we heard of new types of experiments that are exploratory in this respect.”
One can say that the general conclusions of the discussion were a continuation of what has been said during the opening session, namely:
- At the ELI NP pillar we are confronted with a new frontier in physics – the laser-nuclear physics frontier;
We are facing probably the most exciting physics of the moment and
ELI NP is a machine of huge importance, practical aspects included.
This was emphasized by the consensus reached during the closing session, by the fact that the whole Workshop was effectively a working session and did not have any intention to just promote the ELI Project as well as the fact that it has succeeded to achieve what was the original intention, i.e. the quantitative aspects of building this pillar in Romania.
In order to comply with the true scope of the Bucharest pillar, it was decided to give up any reference to “Photonuclear physics”, as being far too restrictive and use exclusively “ELI NUCLEAR PHYSICS”.
It was also decided to set up four working groups: 1. THE LASER, 2. THE GAMMA FACILITY, 3. EXPERIMENTS, 4. CONSTRUCTION. At the proposal of Toshiki Tajima, one has nominated the Chairman - C, Co-Chairman - CC and Secretary - S of each group. For the four groups mentioned they are:
- Jean-Paul Chambaret–C, Georg Korn–CC, Daniel Ursescu–S
- Guy Wormser-C, R. Hajima-CC, Cătălin Borcea-S
- Dietrich Habs-C, Peter Thirolf-CC, Florin Negoiţă-S, Nicolae Marginean-S
- Martin Gross-C, Constantin Ivan-S
There will be an Executive Committee, chaired by Victor Zamfir and having as members all the Chairs, Co-Chairs and Secretaries of the working groups. Each group will be responsible with producing a report. The role of this Committee will be, among other things, to match all the proposals that will be made and to write a “White Book” for this pillar. This document should establish the basic features - for instance: the intensity at least 1023-1024, the gamma flux; the basics of the radioprotection program (contacting the right people in the PP) in order to finalize the Feasibility Study; how big will be the gamma source etc. - and the details of the pillar
Toshiki Tajima and Gerard Mourou proposed to have also an International Advisory Board for the ELI NP pillar. Its mission will be to advise the Executive Committee and to make recommendations for the final form of the “White Book”. This International Advisory Board will be connected to the Scientific Advisory Committee of the ELIPP through the fact that some of the members will be shared among the two. Among the members not belonging also to the ELI PP we asked Alex Muller, as an expert in large infrastructures, Edmond Turcu from RAL, Gunther Rosner , the Chairman of NuPECC and Norbert Pietralla, Director of the Institute of Nuclear Physics, TU Darmstadt .
Gerard Mourou: It was a historical day. It is essential that we have the Proceedings of our works. Each speaker should send a one page Abstract before next February 10. He also emphasized that we shall have here, at the ELI NP pillar, the most powerful laser in the world before the High Fields location will be decided. With a 30 PW laser in Bucharest we can do reasonably good physics at the high intensities available before building the high intensity facility. Of course, we have to
build it, but until then we shall be working here.
Gérard Mourou went against an important misconception plaguing the laser driven particle paradigm as inefficient with respect to conventional technology. He showed that it should have similar wall plug efficiency once an efficient laser driver will be used. The latter will be demonstrated in few years.
We know what experiments we want for the next few years, but afterwards, no. However, we are building this facility for 20-30 years at least. We have therefore to make things adaptable, upgradeable.
Victor Zamfir: Let the groups have the responsibility to propose the experiments – we cannot in any way limit their number. And everything we shall produce will be part of the TDR.
Toshi Tajima: The ELI NP pillar is not a closed concept – it will allow doing practically any type of physics. Therefore, the installation should be designed flexibly. For example, the floor plan has to be modular and can be adjusted to the kind of experiments that require varied degrees of shield (such design philosophy is already considered elsewhere). Also, it is important to have staged gradual expansion of the facility, instead of everything to a full spec at the onset. With respect to using or not superconducting magnets, he said being in favor of the former, but if too expansive we should be flexible and use classical magnets. Again for the gamma source, for example,one can design a staged plan to reduce the entry level cost.
Nicolae Victor Zamfir: In deciding the size of the building and designing it, we should take into account the radioprotection problems – we have to stop at something! As for the location of the Gamma Facility, it has to be chosen in connection with the laser reaction room. Concerning the experimental hall, we certainly could adopt the Darmstadt(or other similar places) way, that is movable walls (big concrete blocks).
Keeping in mind the three main constraints –technical, budgetary and political– he stressed the absolute necessity to have the Feasibility Study before next August. So, we cannot start from scratch and we have to use all the available information from the existing laboratories and from the documents elaborated by the ELI-PP team.