The Extreme Light Infrastructure (ELI) is a major European Infrastructure project, part of the 2006 Roadmap of ESFRI (European Strategic Forum for Research Infrastructure), to be implemented in three locations in the Czech Republic, Hungary,and Romania.
The Nuclear Physics pillar, ELI-NP is located in the Magurele Physics Research Campus, near Bucharest, Romania. Valued at more than 300M Euro, the project is cofinanced by the European Commission and the Romanian Government from Structural Funds, via the European Regional Development Fund. Romania's ELI-NP – overseen by the Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH) – has started to be implemented in 2013, and it is scheduled to be finished by the end of 2018.
In 2019, when the project is going to be operating, it will be the most advanced research facility in the world focusing on nuclear physics studies with photons and applications – a task that will be accomplished with the help of two 10PW ultra-short pulse lasers and the most brilliant tunable gamma-ray beam machine currently available in the world. The brilliant gamma ray beam provides tunable energy of up to 20 MeV, which is obtained by the back-scattering of optical photons on electrons from a LINAC beam of energy up to 720 MeV. [...]

Ultra-intense laser fields, reaching up to 10²²W/cm², are now able to produce typical radiation formerly used in nuclear facilities, as demonstrated in laboratories across the globe. The emerging laser-driven technologies are very promising in terms of cost, size and available parameter range. However, the vast majority of experiments were performed in laboratories where the operation of the laser system did not reach the reliability of the nuclear facilities counterparts. Crossing the gap from lab-based experiment to facility-based experiment was identified in Europe as a major step forward. As a consequence, the construction of a laser-centred, distributed pan-European research infrastructure, involving ultra-short and ultra-intense laser technologies at the state of the art and beyond, was triggered through the Extreme Light Infrastructure (ELI) project. [...]

The Laser Beam Delivery (LBD) system technical design report covers the interface between the High Power Laser System (HPLS) and the experiments, together with the pulse quality management. The laser transport part of the LBD has a number of subsystems as follows: the beam transport lines for the six main outputs of HPLS, the additional short and long pulses and the synchronization system including the timing of the laser pulses with the Gamma Beam System (GBS) and the experiments on femtosecond timescale. Pulse quality management, discussed further here, consist in the generation and delivery of multiple HPLS pulses, coherent combining of the HPLS arms, laser pulse diagnostics on target, laser beam dumps, shutters and output energy adaption.

High power lasers have proven being capable to produce high energy γ-rays, charged particles and neutrons, and to induce all kinds of nuclear reactions. At ELI, the studies with high power lasers will enter for the first time into new domains of power and intensities: 10 PW and 10²³W/cm². While the development of laser based radiation sources is the main focus at the ELI-Beamlines pillar of ELI, at ELI-NP the studies that will benefit from High Power Laser System pulses will focus on Laser Driven Nuclear Physics (this TDR, acronym LDNP, associated to the E1 experimental area), High Field Physics and QED (associated to the E6 area) and fundamental research opened by the unique combination of the two 10 PW laser pulses with a gamma beam provided by the Gamma Beam System (associated to E7 area). [...]

ELI-NP facility will enable for the first time the use of two 10 PW laser beams for quantum electrodynamics (QED) experiments. The first beam will accelerate electrons to relativistic energies. The second beam will subject relativistic electrons to the strong electromagnetic field generating QED processes: intense gamma ray radiation and electron-positron pair formation. The laser beams will be focused to intensities above 10²¹ Wcm^-2 and reaching 10²²-10²³ Wcm^-2 for the first time. We propose to use this capability to investigate new physical phenomena at the interfaces of plasma, nuclear and particle physics at ELI-NP. This High Power Laser System - Technical Design Report (HPLS-TDR2) presents the experimental area E6 at ELI-NP for investigating high field physics and quantum electrodynamics and the production of electron-positron-pairs and of energetic gamma-rays. [...]

We propose experiments in the E7 and E4 experimental areas at ELI-NP to tackle problems of fundamental physics, taking advantage of the unique configuration and characteristics of the new research infrastructure to be constructed in Magurele, Romania. The experimental setups proposed follow a gradual approach from the point of view of complexity, from the "Day 1" experiments to experiments for which the prerequisites include results from the previously performed ones. In addition, there are two generic Research and Development tasks proposed in this Technical Design Report (TDR), related to the development of a detection system, Gamma Polari-Calorimeter (GPC), commonly applicable to energy measurements for electrons, positrons and gamma-rays above the 0.1 GeV energy scale and the preparatory tests for laser plasma acceleration of electrons up to necessary energies 210 MeV, 2.5 GeV and 5 GeV for the later stage experiments, respectively. In this paper we particularly focuson possible "Day-1" topics and briefly mention the future extensions foreseen.

As a leading facility in laser-driven nuclear physics, ELI-NP will develop innovative research in the fields of materials behaviorin extreme environments and radiobiology, with applications in the development of accelerator components, new materials for next generation fusion and fission reactors, shielding solutions for equipment and human crew in long term space missions and new biomedical technologies. The specific properties of the laser-driven radiation produced with two lasers of 1 PW at a pulse repetition rate of 1 Hz each are an ultra-short time scale, a relatively broadband spectrum and the possibility to provide simultaneously several types of radiation. Complex, cosmic-like radiation will be produced in a ground-based laboratory allowing comprehensive investigations of their effects on materials and biological systems. The expected maximum energy and intensity of the radiation beams are 19 MeV with 109photon/pulse forphoton radiation, 2 GeV with 10⁸ electron/pulse for electron beams, 60 MeV with 10¹² proton/pulse for proton and ion beams and 60 MeV with 10⁷ neutron/pulse for a neutron source. Research efforts will be directed also towards measurements for radioprotection of the prompt and activated dose, as a function of laser and target characteristics and to the development and testing of various dosimetric methods and equipment.

The current TDR describes the requirements for the experiments taking place in areas E1-E8 of the ELI-NP facility, in terms of monitoring and control, specifying input/output signals, estimated data fluxes, storage necessity, synchronization, vacuum control and monitoring, reliability, maintenance, integration with subsystems and other transverse needs. Based on this information,follows the design and implementation details of a modular architecture that will fit the ELI-NP starting needs and will permit further development.

The high brilliance Gamma Beam System at ELI-NP is based on theInverse Compton Scattering of laser light on relativistic electron bunches provided by awarm radio-frequency linear accelerator. The system will deliver quasi-monochromaticgamma-ray beams (bandwidth 0.5%) with a high spectral density (10,000 photons/s/eV)and high degree of linear polarization (99%). [...]

The development at ELI-NP of a new laser-based Inverse Compton Scattering gamma beam system, featuring extremely high intensities at very narrow bandwidths, opens new and important opportunities in nuclear science research. Nuclear photonics is undergoing a revival, the gamma beams with unprecedented features delivered at ELI-NP paving the way for high accuracy and detailed nuclear physics studies. A wide range of industrial, homeland security and healthcare applications will also experience an important boost. The combination of nuclear photonics with the technique of Nuclear Resonance Fluorescence (NRF) allows for the recovery of severalphysical quantities characterizing the excited nuclear states in a completely model independent way. These observables include the excitation energies, level widths, gamma-decay branching ratios, spin quantum numbers, and parities. [...]

This Technical Design Report describes the physics cases and instrumentation proposed by the ELI-NP Working Group "Gamma Above Neutron Threshold" (hereafter ELIGANT). Extremely high-intensity and monochromatic γ-ray beams available at the ELI-NP allow us to enter a precision era of investigating electromagnetic responses of atomic nuclei. The ELIGANT group addresses the following 4 physics cases related to: p-process nucleosynthesis, Nuclear structure of Giant Dipole Resonance (GDR), New Compilation of total and partial photoneutron cross sections, Nuclear structure of Pygmy Dipole Resonance (PDR) and spin-flip Magnetic Dipole Resonance (MDR). [...]

Three photofission experimental programs are proposed to be carried out with the brilliant gamma beams that will be available at the ELI-NP facility. First, we will measure the absolute photofission cross-sections of actinide targets and will study the energy, mass and charge distributions of fission fragments,as well as of ternary fission. We further propose to measure the angular distribution of photofission fragments. One of the goals is to resolve the fine structure of the isomeric shelf and to observe the clusterisation phenomena in super-and hyper-deformed actinide states. For this, an array of Bragg ionization chambers and an array of thick gas electron multipliers will be constructed. Second, the structure of exotic nuclei produced in photofission will be studied, in particular, isotopes of refractory elements, by developing an ISOL-type facility with an ion-guide, a RFQ ion cooler and a mass separator to separate and transport the isotopes of interest to the measurement stations. Last, we aim at studies of g-factors of short-lived nanosecond isomers since they are difficult to be measured anywhere else. For measurements and studies of the γ decay of excited states in exotic nuclei, we intent to use the detectors of the ELIADE array.

We propose charge particle detectors to be used in measurements utilizing intense gamma-ray beams from the newly constructed ELI-NP facility at Magurele, Bucharest in Romania. We consider a large area Silicon Strip Detector (SSD) and a gas Time Projection Chamber detector read by an electronic readout system (e-TPC). We intend to use the SSD and e-TPC detectors to address essential problems in nuclear structure physics, such as clustering and the many alpha-decay of light nuclei such as ¹²C and ¹⁶O. The e-TPC detector may be also used for studies in nanodosimetry and radiation damage to DNA (research described in the Medical Applications TDR of ELI-NP, RA4-TDR5). Both detectors (SSD and e-TPC) will be used to address central problems in nuclear astrophysics such as the astrophysical cross section factor of the 12C(α,γ) reaction and other processes central to stellar evolution. We identify the infrastructure required in Romania and other countries to facilitate the construction of these detectors as well as the required budget and personnel. Memorandums of Understanding (MOUs) between the ELI-NP facility and the collaborating institutes have been signed in order to permit the realization of this Technical Design Report (TDR).

We propose to obtain an intense beam of moderated positrons (e_s⁺) with an intensity of the primary positron beam of 1×10⁶ -2×10⁶e_s⁺s⁻¹ by the (γ, e⁺e^-) reaction using an intense γ-beam of 2.4×10¹⁰γs^-1 with energies up to 3.5 MeV. Using fully circularly polarized γ-beam we aim to obtain an intense, polarized positron beam with a polarization degree of 31-4 5%. Higher degree of polarization would also be possible with reduced beam intensity. The beam will be transported to different detector systems through beam lines, via solenoidal magnetic fields. Polarized positron beams open up a totally unexplored research area in applied physics studies of Fermi-surfaces, defects, interfaces etc., where polarized electrons can be studied. A simple, fast scintillatordetector system for γ-induced positron annihilation lifetime spectroscopy for studies of bulk samples is proposed. The ELI-NP facility will be user-dedicated and unique for positron research in the Eastern Europe. It will provide a simple source setup, with easy access for upgrades of the converter/moderator assembly toward more sophisticated setups, providing a more intense and brighter positron beam. The beam will have the world highest intensity of polarized positrons for material science studies and, therefore, it will become a unique tool for the investigation of magnetic samples.

An ultra-bright, energy tunable and monochromatic gamma-ray source in the range of 0.2–19.5 MeV produced by Laser-Compton Backscattering technique is ideal for non-destructive testing applications. Consequently, this source satisfies the criteria for large-size product investigations with added capabilities like isotope detection through the use of nuclear resonance fluorescence (NRF) technique. This document presents the technical description of two major industrial applications of gamma beams envisaged at ELI-NP: industrial applications based on NRF and industrial radioscopy and tomography. Both applications exploit the unique characteristics of the gamma beam to deliver new opportunities for the industry. The non-destructive assay based on high-brightness gamma rays can be successfully applied for safeguard applications and management of radioactive wastes. Radioscopy and computed tomography performed at ELI-NP has the potential to achieve high spatial resolution and high contrast sensitivity. The performance of the experimental setups proposed is discussed in de-tail in sections 2.3 and 3.3; the performance figures cited there are based on analytical calculations and numerical simulations.

The radioisotope production hasa crucial role in medical diagnostic imaging or therapy. Historically, the radionuclides were produced using accelerated beams or nuclear reactors. The radioisotopes are used to precisely localize the pathological processor treat the illness by selectively targeting the site using a bioactive molecule as carrier. The applications of radioisotopes in molecular nuclear medicine require high specific activity, which can be usually obtained using nuclear reactions induced by high intensity accelerated beams of light charged particles or neutrons comingfrom nuclear reactors. The radioactive element is transmuted from the target isotope and can beseparated by chemical procedures. [...]

In the present report we propose radiological protection and dosimetry technical systems for ELI-NP facility. The study includes assessments of the facility's radiological installations and experimental areas, as well the location and nature of detectors/instruments that should be appropriate to cover the three main areas of dosimetry for ELI-NP: personnel dosimetry, area dosimetry and environment dosimetry. The devices dedicated to the above first three items must fulfil the legal requirements provided by the regulatory bodies in this field, and will also serve to obtain the operational licenses from the Romanian Nuclear Authority (CNCAN). In order to fulfil the regulatory requirements (Romanian and International) we consider mandatory to consult calibration facilities and methods for the dosimetric systems special characteristics. We identified the structure required in Romania and European countries and a common organizational plan to efficiently design, supervise and monitor all aspects of safety, radiological protection and dosimetry for ELI-NP, as well the required budget and personnel.