The BECQUEREL Project: Progress Report for Years and Plans for D. A. Artemenkov, V. Bradnov, A. I. Malakhov, D. O. Krivenkov, P. A. Rukoyatkin, V. V. Rusakova, T. V. Shchedrina, P. I. Zarubin, I.G Zarubina V. I. Veksler and A. M. Baldin Laboratory of High Energy Phyiscs,JINR, Dubna, Russia M. M. Chernyavsky, S. P. Kharlamov, S. G. Gerasimov, L. A. Goncharova, G. I. Orlova, N. G. Peresadko, N. G. Polukhina P. N. Lebedev Physical Institute RAS, Moscow, Russia М. Haiduc, A. Neagu,E. Stefan М. Haiduc, A. Neagu, E. Stefan Institute of Space Sciences, Bucharest-Magurele, Romania A. A. Moiseenko, V. R. Sarkisyan Erevan Physical Institute, Erevan, Armenia R. Stanoeva Institute for Nuclear Research and Nuclear Energy BAS, Sofia, Bulgaria S. Vokal Safarik University, Kosice, Slovakia

The BECQUEREL Project (Beryllium (Boron) Clustering Quest in Relativistic Multifragmentation) at the JINR Nuclotron is devoted systematic exploration of clustering features of light stable and radioactive nuclei. A nuclear track emulsion is used to explore the fragmentation of the relativistic nuclei down to the most peripheral interactions - nuclear "white" stars. This technique provides a record spatial resolution and allows one to observe the 3D images of peripheral collisions. The analysis of the relativistic fragmentation of neutron-deficient isotopes has special advantages owing to a larger fraction of observable nucleons. Nuclear beams of energy higher than 1A GeV are recognized as a novel opportunity for the nuclear structure explorations. Among all variety of the nuclear interactions the peripheral dissociation bears uniquely complete information about the excited nucleus states above particle decay thresholds.

Superposition of microphotographs of interaction of relativistic nucleus 32 S and human hair taken with MBI-9 microscope and NIKON camera Nuclear Track Emulsions

NUCLOTRON: 2.1 А GeV 14 N Tatjana Shchedrina 132 events 1.2A GeV 14 N → 3He + H 50 “white” stars ( 2 events 6 He+ 3 He+ 4 He+ 1 H )

Nuclear Clustering Physics Program

CO2 laser

Z pr /A pr = 4/9 10 B → 9 Be.

370 events 1.2 A GeV 9 Be→2He 39 stars with heavy fragment of target nucleus (b-particle) 144 “white” stars +1.7 MeV 27 stars with target proton recoil (g-particle ) Denis Artemenkov

0 +, 8 Be(92 KeV, 6.8 eV) 2 +, 8 Be(2.9 MeV, 1. 5 MeV )

Suggested analysis: 2000 events 9 Be + p → 2α 9 Be + p → 2α Nadezhda Kornegrutsa

Z pr /A pr = 4/7 7 Li → 7 Be

1.6 MeV

Zpr/Apr = 5/8 10 B → 8 B

Nearer approach of the nuclei with an impact parameter (a), absorption of quasireal photon by 8B nucleus (b), 8B dissociation on fragment pair - p and 7Be (c). Diagram of peripheral dissociation of relativistic 8B nucleus in EM field of Ag nucleus

8 В (1.2 A GeV) → 7 Ве + p Ralica Stanoeva

8 B → 2 3 He + 2 H 8 B → 2 3 He + 2 H

Zpr/Apr = 2/3 12 C → 9 C

Major task: analysis of 9 Сexposure analysis of 9 С exposure Dmitry Krivenkov

Z pr /A pr = 5/12 12 C → 12 N

Suggested 10 C exposure

10 С

1.0 A ГэВ 10 B→2 3 Не+ 4 Не

Suggested 11 C exposure

2.0 A GeV 11 B→ 4 Не+ 7 Be

CONCLUDING REMARKS The presented observations serve as an illustration of prospects of the Nuclotron for nuclear physics and astrophysics researches. In spite of an extraordinarily large distinction from the nuclear excitation energy the relativistic scale does not impede investigations of nuclear interactions down to energy scale typical for nuclear astrophysics, but on the contrary gives advantages. The major one of them is the possibility of principle of observing and investigating multi-particle systems. The investigations with light nuclei provide a basis for challenging studies of increasingly complicated systems He – H - n produced via multifragmentation of heavier relativistic nuclei in the energy scale relevant for nuclear astrophysics. In this respect, the motivated prospects are associated with a detailed analysis of the already observed fragment jets in the events of EM&Diffractive dissociation of Au nuclei at 10.6A GeV and Pb nuclei at 160A GeV. Due to a record space resolution the emulsion technique provides unique entirety in studying of light nuclei, especially, neutron-deficient ones. Providing the 3D observation of narrow dissociation vertices this classical technique gives novel possibilities of moving toward more and more complicated nuclear systems. Therefore this technique deserves upgrade, without changes in its detection basics, with the aim to speed up the microscope scanning for rather rare events of peripheral dissociation.

3.65A GeV 28Si

NUCLOTRON: 1A GeV 56 Fe Elena Stefan Alina-Tania Neagu

SPS: 158 A GeV/c Pb

Наименование узлов и систем установки, ресурсов, источников финансирования Стоимость узлов (тыс.долл.) установки. Потребности в ресурсах Предложения лабораторий по распределению финансирования и ресурсов 1 г.2 г.3 г.4 г.5 г. Основные узлы и оборудование1.Датчики для микроскопов 2.Электроника, ФЭУ 1.20 тыс. дол тыс.долл. 35 тыс. долл. 25 тыс. долл. 20 тыс. долл. Необходимые ресурсы нормо ОП ОИЯИ – механические работы – электроника КБ ЛАБОРАТОРИЯ ООЭП 1 чел. год час Ускоритель (Нуклотрон) Реактор ЭВМ (тип) 100 Эксплуатационные расходы Источники финансирования бюджет Затраты из бюджета, в том числе инвалюные средства 80 тыс. долл. 35 тыс. долл. 25 тыс. долл. 20 тыс. долл. внебюджетные Вклады коллаборантов Средства по грантам Вклады спонсоров Средства по договорам Другие источники и т.д.

1. Фотоумножители (Hamamatsu, Photonis) 700 Euro 7 шт Euro 2. Зарядово-цифровой преобразователь CAEN C1205 или аналогичный 4000 Euro 1 шт Euro 3. Материалы и радиоэлектронные комплектующие детекторов и приемной электроники 2500 Euro 3000 Euro 4. Осциллограф TDS3000B 8000 Euro 1 шт Euro Итого: Euro Запрос на приобретение электронной аппаратуры формирования пучков на гг. (7000 Euro в год)

8 В (1.2A GeV) → 2Не + Н

Measured Charges of Secondary Fragments of 8 В Nucei Density of δ-electrons per 1 мм length of beam particles Z fr > 2.

8 B: Total P T ( 7 Be+p) EMD “white”stars nh≠0nh≠0nh≠0nh≠0