Skip to content

Welcome to LUNA - Padova Laboratory for Underground Nuclear Astrophysics

The Laboratory for Underground Nuclear Astrophysics (LUNA) is a nuclear astrophysics experiment running at the INFN (Istituto Nazionale di Fisica Nucleare) Gran Sasso National Laboratories.

The aim of the experiment is to measure directly the cross sections of the most important fusion reactions for stellar hydrogen burning and nucleosynthesis as well as Big Bang nucleosynthesis at astrophysical temperatures. To achieve this goal, two high current accelerators have been installed in the underground Gran Sasso laboratory: a 50 kV accelerator equipped with a windowless gas target and a 400 kV machine equipped with a solid target beam line and a windowless gas target.

Contact us

Antonio Caciolli (local coordinator)

Email: antonio.caciolli@pd.infn.it

About

Nuclear fusion reactions generate most of the energy irradiated by stars. Moreover, nuclear reactions are responsible for the synthesis of the elements both in the early Universe and in stars. At astrophysical temperatures, nuclear fusion reactions can only take place in a relatively narrow energy window: the Gamow peak. In this region, which is in most cases far below the Coulomb repulsion energy, the reaction cross-section drops exponentially with decreasing energy. The extremely low cross sections, from 10-33 to 10-39 cm2 and even smaller, are difficult to measure in a laboratory at the Earth’s surface because the expected counting rate is much smaller than the background in a detector.

In a gamma ray detector, the background origin is twofold: below 3 MeV it is maily due to the decay of environmental radioactive isotopes (uranium and thorium chains and 40K). This background can be substancially reduced by shielding the detector with lead or copper. Above 3 MeV, the main source of environmental background is cosmic radiation. At sea level, most of the cosmic radiation is made of muons and the most efficient way to suppress the muon-induced background is to perform experiments in underground laboratories.

In order to explore this new domain of nuclear astrophysics we have installed two electrostatic accelerators underground in Gran Sasso National Laboratories (LNGS): first a 50 kV machine (LUNA I, 1992-2001) and then a 400 kV machine (LUNA II, 2000 – today).

Fig. 1 Map of the Gran Sasso National Laboratories and locations of the LUNA I and LUNA II facilities.

Outstanding features of both accelerators are a very small beam energy spread and a very high beam current even at low energy. Windowless gas targets or high purity solid targets have been mounted in our set-up, whereas silicon detectors, a 4π BGO summing crystal and ultra-high purity germanium detectors are being used for particle and γ-ray detection.

At Gran Sasso National Laboratories, the cosmic muon flux is suppressed by six orders of magnitude. As a consequence, the background observed in a gamma ray detector is also suppressed by orders of magnitude

Fig. 2 Gamma ray background measured with a HPGe detector at the Earth’s surface and at LNGS.

Thanks to the very low background conditions at LUNA, it was possible to measure the cross sections of several nuclear reactions of interest for stellar hydrogen burning and Big Bang nucleosynthesis.

To learn more about the LUNA experiment, visit the LUNA Official web page

People

P.h.D. student

Master student

  • Riccardo Biasissi 
  • Anna Vigolo
  • Aravind Remesan Sreekala  
  • Chiara Baron 
  • Lucia Barbieri

Opportunities

 
  • PhD call is opening soon. Stay tuned!
  • We offer a good number of bachelor and master thesis, see a list here (look for antonio.caciolli@unipd.it).

News

01.02.2024

Welcome Steffen!

Dr. Steffen Turkat has just joined our group as a Post Doc. He completed his PhD at TU Dresden with the thesis: “Primordial Nuclides and Low-Level Counting at Felsenkeller”. His Post Doc position is funded in the frame of the PRIN project CaBS (see below). Steffen will be in charge of the detection system for the 12C+12C measurement at LNGS! 

15/01/2024

LUNA General Meeting for the first time in Padova! 

For the first time during LUNA history the General Meeting was held in Padova. 

01/01/2024

GIANTS newsletter is out!

15/12/2023

Making Astrophysics Accessible

In the frame of the project “Stelle sulla Terra”, we organized a seminar on “The advantages of making science accessible”, which was held by Dr. Erika Labbé Waghorn (Instituto de Estudios Astrofísicos, Universidad Diego Portales – Cile).  As follow up of the seminar, a two days hands on workshop was held by Erika and make us facing the challenges behind making science accessible. 

12.12.2023

Congratulations Jakub!

Jakub successfully discussed his PhD thesis “Complete Study of Proton Capture on Carbon Isotopes at Astrophysical Energies”.  Jakub has now a post doc position in our group.

01/09/2023

CaBS project got the PRIN

CaBS project on 12C+12C LUNA measurement at LNGS got the PRIN from the MIUR! LUNA-PD is deeply involved in the project.

01/09/2023

Stelle sulla Terra project has started!

Network and Other Projects

 

Gallery