The funding of the ELI-NP project from Structural Funds was approved by the European Commission




  Research Activities - RA2 - High-Brilliance Gamma Beam

Research Activity 2 - "High brilliance gamma beams" is dedicated to the development and operation of a high flux, high brilliance, monochromatic, energy tuneable gamma-beam production system based on laser inverse Compton scattering off relativistic electron bunches.

The Gamma Beam System at ELI-NP defines a new state–of–the–art gamma beam facility. It will provide gamma beams with energy continuously tunable between 200 keV and 19.5 MeV, relative bandwidth better than 0.5% and a spectral density higher than 5 x 103 photons/s/eV. (More at

Conceptually, the system is composed of a laser providing photon pulses that are up-shifted in energy to MeV range or above through collision with relativistic electron bunches produced by a normal temperature radiofrequency (RF) linear accelerator. The resulting (incoherent) gamma rays form a low divergence microbeam that can be well defined in energy by adequate collimation.

The design and implementation of the Gamma Beam System at ELI-NP is performed by the European Association EuroGammaS in which academic institutions such as INFN (Italy), CNRS (France) and Sapienza University (Italy) have joined the efforts with industrial partners: ACP Systems (France), ALSYOM (France), COMEB (Italy), SCANDINOVA Systems AB (Sweden).

The main components of the Gamma Beam System are:
  1. RF linac for the acceleration of electrons to relativistic energies; the accelerator is designed in two stages: one for energies up to about 300 MeV and a second one for energies up to about 720 MeV; electrons are produced by a laser-driven multi-bunch RF photogun at a repetition rate of 100 Hz in 32 bunches of 250 pC each and separated at 16 ns; the high-luminosity photoinjector comprises two SPARC-type S-band acceleration structures; acceleration of the electrons is performed with 12 C-band acceleration structures;
  2. interaction lasers of cryo-cooled Yb:YAG J-class type providing laser pulses of 515 nm wavelength and 200 mJ energy at 100 Hz repetition rates;
  3. laser beam circulators to ensure the interaction of the laser pulses provided at 100 Hz repetition rate with the 32 electron bunches delivered by the RF linac every 10 ms;
  4. gamma beam collimators consisting of a stack of vertical Ti dual-slit elements rotated one respect to the other; the aperture of the collimators can be optimized for every energy of the gamma beam and according to the targeted bandwidth;
  5. diagnostics stations to characterize the gamma beams are placed after the interaction points; they will provide information on the energy, bandwidth, intensity and spatial profile of the gamma beams after the collimators.

A unique control system will manage the whole machine from the photogun to the gamma beam diagnostics allowing for the execution of commands on all active elements and control all diagnostics devices and providing information to the machine operators. The control system is implemented in EPICS framework.

A full description of the Gamma Beam System at ELI-NP is available at


Calin A. UR   Head of RA2 - Research Scientist I   CV / Publications
Stephan TZENOV   Research Scientist II  
Marian TOMA   RA2 Deputy - Research Scientist III   CV / Publications
Dorina ARANGHEL   Research Scientist III   CV / Publications
Alexandru BOIANU   Engineer  
Guangling CHEN   Engineer   CV / Publications
Mihai CIUBANCAN   Engineer  
Alexandru IMREH   Engineer  
Cristian PETCU   Engineer   CV / Publications
Bogdan TATULEA   Engineer  
Piotr TRACZ   Engineer   CV / Publications
Emil UDUP   Engineer  
Cornel Dinu CIRDEI   Electrical Engineer  
Alfio PAPPALARDO   Physicist  
Iani MITU   Postdoctoral Research Assistant  
Gabriel TURTURICA   PhD Student  
Valeriu BUZNEA   Technician  
Ioan GARAGAIANU   Technician  

Previous members

Cristian SAVLOVSCHI   Engineer  
Teodor DOGARU   Postdoctoral Research Assistant  
Marcel CONDE   Postdoctoral Research Assistant  
Cristian PAUN   Postdoctoral Research Assistant  
Violeta IANCU   Research Scientist III  
Gabriel SULIMAN   Research Scientist III  

The content of this document does not necessarily represent the official position of the European Union or of the Government of Romania.
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