Low-pressure TPC detector for studying photonuclear reactions at astrophysical energies with gamma-ray beams at ELI-NP

18 janv. 2018 à 10:00
Aula Magna, Facultad de Física (Santiago de Compostela)

Aula Magna, Facultad de Física

Santiago de Compostela

Facultade de Física. Campus Vida s/n | E-15782, Santiago de Compostela | Galicia, Spain


Dr Mikolaj Cwiok (University of Warsaw)


The Extreme Light Infrastructure-Nuclear Physics (ELI-NP) facility will provide monochromatic, high-brilliance and polarized gamma-ray beams, which can be used to study nuclear reactions of current astrophysical interest through the inverse photo-dissociation processes and detailed balance principle. In particular, of special interest are (p, $\gamma$) and ($\alpha$, $\gamma$) reactions that regulate the ratio of C and O and those that burn $^{18}$O and, therefore, regulate the ratio between $^{16}$O and $^{18}$O in the Universe. For instance, the benchmark inverse kinematic reaction $^{12}$C($\gamma$, $\alpha$)$^{16}$O can be investigated down to 1 MeV in the centre-of-mass reference frame, where experimental data from direct experiments are sparse.

A dedicated Time Projection Chamber (ELITPC) with an active gaseous target kept under low pressure is being developed at University of Warsaw, IFIN-HH/ELI-NP and University of Connecticut. The active target volume of ELITPC will be about 35 $\times$ 20 $\times$ 20 cm$^3$ and will be centered around gamma-beam axis. The reaction products stopped in the gas will produce primary electrons that drift towards charge amplification structures made of Gas Electron Multiplier (GEM) foils. The three-dimensional kinematics of the photo-dissociation events will be reconstructed from about 10$^3$ signal strips, arranged into redundant, 3-coordinate system.

High intensity $\gamma$ beams are expected to be available at ELI-NP ($\sim$10$^7$ photons/bunch, 100 Hz bunch repetition rate). The beam-induced background has been studied using Monte Carlo techniques for different $\gamma$ beam profiles, in order to optimize the expected signal to background ratio. Several scaled demonstrator detectors were constructed and tested with alpha-particle and X-ray sources.

The results from ongoing R$\&$D activities for this project will be presented.

Auteur principal

Dr Mikolaj Cwiok (University of Warsaw)

Documents de présentation

Your browser is out of date!

Update your browser to view this website correctly. Update my browser now