C. E. Demonchy

First direct observation of two protons in the decay of 45Fe with a time-projection chamber.

The decay of the ground-state two-proton emitter 45Fe was studied with a time-projection chamber and the emission of two protons was unambiguously identified. The total decay energy and the half-life measured in this work agree with the results from previous experiments. The present result constitutes the first direct observation of the individual protons in the two-proton decay of a long-lived ground-state emitter. In parallel, we identified for the first time directly two-proton emission from 43Cr, a known beta-delayed two-proton emitter. The technique developed in the present work opens the way to a detailed study of the mechanism of ground state as well as beta-delayed two-proton radioactivity.

Tracking algorithms for the active target MAYA

Abstract The MAYA detector is a Time-Charge Projection Chamber based on the concept of active target. These type of devices use a part of the detection system, the filling gas in this case, in the role of the reaction target. The MAYA detector performs three-dimensional tracking, in order to determine physical observables of the reactions occurring inside the detector. The reconstruction algorithms of the tracking use the information from a two-dimensional projection on the segmented cathode, and, in general, they need to be adapted for the different experimental settings of the detector. This work presents some of the most relevant solutions developed for the MAYA detector.

Comparison Of Expected Yields For Light Radioactive Beams At SPIRAL‐1 And 2

Light‐particles stable high‐intensity beams (p, d, 3,4He…) will be available from the Linac driver accelerator of SPIRAL‐2. Yields of neutron‐deficient isotopes as well as of neutron‐rich isotopes (by means of reactions with secondary neutrons) are compared with those presently available at the SPIRAL‐1 facility. We explore, for light beams (Z<16) asked in the ‘white book’ of SPIRAL‐2, the production methods taking into account the in‐target yield but also the feasibility of making such beams by the ISOL method (considering reaction, target, thermal and release properties). We discuss some of the tests needed and planned. A comparis on with the present and potentially attainable yields at SPIRAL‐1 is presented.

β‐delayed emission of protons at the proton drip‐line: the cases of 43Cr and 51Ni

Studies of {beta}-delayed emission of protons for {sup 43}Cr and {sup 51}Ni were performed with a Time Projection Chamber. This detection setup allows to reconstruct in the three-dimensional space the tracks of the protons emitted. For the first time, {beta}-delayed emission of two protons is directly observed for {sup 43}Cr and {sup 51}Ni. The question about correlations between protons can be accessed. Finally, we show that {sup 43}Cr can emit up to three delayed protons.

β-delayed emission of protons at the proton drip-line: the cases of [sup 43]Cr and [sup 51]Ni

Studies of {beta}-delayed emission of protons for {sup 43}Cr and {sup 51}Ni were performed with a Time Projection Chamber. This detection setup allows to reconstruct in the three-dimensional space the tracks of the protons emitted. For the first time, {beta}-delayed emission of two protons is directly observed for {sup 43}Cr and {sup 51}Ni. The question about correlations between protons can be accessed. Finally, we show that {sup 43}Cr can emit up to three delayed protons.

2p radioactivity studies with a TPC

After the discovery of two‐proton radioactivity in 2002, an important effort has been made in order to observe each emitted particle individually. Energy and angular correlations between the protons should reveal details about the mechanism of this exotic decay mode. In this framework, an experiment has been performed at LISE/GANIL, where the two protons emitted in the decay of 54Zn have been individually observed for the first time. Angular and energy correlations were determined and allowed a first comparison with theoretical predictions.

Experimental Studies Of An Exotic Decay Mode At The Proton Drip-Line: The Two-Proton Radioactivity

Two‐proton radioactivity is an exotic decay mode for very proton‐rich nuclei. It was observed experimentally for the first time in 2002 for the nucleus 45Fe but the two protons could not be directly detected. So a new detector has been developed, a Time Projection Chamber, to individually observe the two protons emitted. It was used successfully during two experiments for the study of 45Fe and 54Zn. Energy correlations have been studied and the relative angle between the two protons is calculated.

Studies with Exotic Nuclei: Two Proton Radioactivity

In the present paper, we present measurements that led to the discovery of two‐proton radioactivity. After the first observation of this decay mode for 45Fe, new measurements evidenced this decay mode also for 54Zn and most likely 48Ni. A new detector based on the time‐projection chamber principle allowed now to visualize the two protons directly.

Observation Of Individual Particles In The Two‐Proton Radioactivity With A Time Projection Chamber

After the recent discovery of two-proton radioactivity, an important effort has been made in order to observe each emitted particle individually. Such kind of studies may result in energy and angular correlation measurements of the protons, which are required to give a precise theoretical description of this exotic decay mode. In this frame, we performed an experiment at the GANIL/SISSI/LISE3 facility, where we used a Time Projection Chamber to observe tracks of protons in the decay of {sup 45}Fe, produced in projectile fragmentation reactions.