N. V. Zamfir

Extreme Light Infrastructure – Nuclear Physics

The Extreme Light Infrastructure (ELI) is an ESFRI-listed distributed facility that entered the implementation phase. The Romanian pillar will focus on the field of nuclear physics research, performed with the help of an ultra-short-pulse, multi-petawatt scale laser system and a brilliant, tuneable and highly collimated gamma beam system. ELI-Nuclear Physics, an open-access facility, shall become operational and receive the first visiting research teams in 2017. We report herein on the status of the implementation and some of the research topics proposed for ELI-NP.

Extreme light infrastructure nuclear physics (ELI-NP): present status and perspectives

Extreme Light Infrastructure (ELI) Pan-European facility initiative represents a major step forward in quest for extreme electromagnetic fields. Extreme Light Infrastructure – Nuclear Physics (ELI-NP) is one of the three pillars of the ELI facility, that aims to use extreme electromagnetic fields for nuclear physics and quantum electrodynamics research. At ELI-NP, high power laser systems together with a very brilliant gamma beam are the main research tools. Their targeted operational parameters are described. The related experimental areas are presented, together with the main directions of the research envisioned.

New frontiers in nuclear physics with high-power lasers and brilliant monochromatic gamma beams

The development of high power lasers and the combination of such novel devices with accelerator technology has enlarged the science reach of many research fields, in particular particle and nuclear physics, astrophysics as well as societal applications in material science, nuclear energy and applications for medicine. The European Strategic Forum for Research Infrastructures has selected a proposal based on these new premises called the Extreme Light Infrastructure (ELI). The ELI will be built as a network of three complementary pillars at the frontier of laser technologies. The ELI-NP pillar (NP for nuclear physics) is under construction near Bucharest (Romania) and will develop a scientific program using two 10 PW lasers and a Compton back-scattering high-brilliance and intense low-energy gamma beam, a combination of laser and accelerator technology at the frontier of knowledge. This unique combination of beams that are unique worldwide allows us to develop an experimental program in nuclear physics at the frontiers of present-day knowledge as well as society driven applications. In the present paper, the technical description of the facility as well as the new perspectives in nuclear structure, nuclear reactions and nuclear astrophysics will be presented.

New light in nuclear physics: The extreme light infrastructure

Extreme Light Infrastructure-Nuclear Physics (ELI-NP), to become operational in 2019, is a new Research Center built in Romania that will use extreme electromagnetic fields for nuclear physics research. The ELI-NP facility will combine two large equipments with state-of-the-art parameters, namely a 2 × 10 PW high-power laser system and a very brilliant gamma-beam system delivering beams with energies up to 19.5 MeV. The laser and gamma-beam systems under construction and typical proposed first-phase experiments are described.

Improvements of the research infrastructure at the tandem laboratory in IFIN-HH

An extensive process of modernizing the research infrastructure started 6 years ago at the tandem accelerator in IFIN-HH. Major improvements of the 9 MV FN tandem accelerator installed in IFIN-HH in ′73 were done in the late years, making it a very reliable machine, suited for basic and applied research experiments. The developments opened the way for new experiments made for the first time in our laboratory. Two new Cockroft-Walton tandem accelerators were also installed in 2012. The 1 MV HVE Tandetron accelerator is dedicated to AMS measurements, especially for 14C dating, while the 3 MV HVE Tandetron accelerator has the reaction chambers and detection system prepared for ion beam analysis measurements, microprobe experiments and ion implantation.

7Li-induced reactions for fast-timing with LaBr3:Ce detectors

7Li induced-reactions have been used with a 186W target to populate nuclei around A∼180-190 at the National Institute of Physics and Nuclear Engineering in Bucharest, Romania. An array of high-purity germanium (HPGe) and cerium-doped lanthanum bromide (LaBr3:Ce) detectors have been used to measure sub-nanosecond half-lives with fast-timing techniques. The yrast 2+ state in 190Os was measured to be t1/2 = 375(20)ps, in excellent agreement with the literature value. The previously unreported half-life of the 564-keV state in 189Ir has also been measured and a value of t1/2 = 540(100)ps ps obtained.

Electromagnetic Transition Rate Measurements in the N=80 Isotone, 138Ce

A study of intrinsic state halflife measurements in the N=80 nucleus 138Ce has been made using the 130Te(12C,4n)138Ce fusion evaporation reaction at beam energy of 56 MeV. The fast-timing gamma-ray coincidence method was used with a mixed LaBr3(Ce)-HPGe array to establish the lifetimes of the yrast 6+ state at 2294 keV, the Iπ=5− state at 2218 keV, the Iπ=11+ state at 3943 keV and the 14+ state at that at 5312 keV, all of which are in the sub nanosecond regime. Reduced transition probabilities have been calculated for the electromagnetic decays from these states.

Half-life of the Iπ = 4− Intruder State in 34P Using LaBr3:Ce Fast Timing

The half-life of the Iπ = 4− intruder state at 2305 keV in 3415P19 has been measured using γ-ray coincident fast timing with LaBr3:Ce scintillation detectors. Excited states in 34P were populated in the 18O(18O,pn)34P reaction at a beam energy of 36 MeV at the Tandem Laboratory at the National Institute of Physics and Nuclear Engineering, Bucharest, Romania. A half-life of t1/2 ~ 2 ns was obtained for the 4− state, giving an M2 reduced transition probability consistent with similar transitions in this mass region and confirming the intruder-parity nature of the state.