1. ACTAR @ R3B p,A scattering at intermediate energies : 700 MeV/u Low momentum transfer : -t < 0.05 (GeV/c) ̂ 2 Exotic nuclei with T(1/2) < 1 sec. Example: 132Sn (39.7 sec.)

2. p,A elastic scattering scheme Cylinder with Be windows 500 um Beam shield d = 2 cm Beam tracking + vertex reconstruction Pressure P in the range 10 to 20 bar

3. p,A scattering : measurement p(132Sn,132Sn) – 700 MeV/u Glauber differential cross sections 0.005 < -t < 0.028 (GeV/c) ̂ 2 3.05° < theta < 7.18° in the CM frame First diffraction minimum With a 5000 beam pps, we achieve < 1% statistical errors

4. Sensitivity to RMS matter distribution

5. Energy resolution for spectroscopic studies

6. Beam E loss and straggling Scattering at 0, 50 cm and 1 m Contribution from the Be windows => thinner ? Large signal from the beam => Shielding Straggling still acceptable at 20 bar E loss correction => Vertex reconstruction

7. Protons Maximum energy stopped in 50 cm : 9.1 MeV (10 bar) and 13.3 MeV (20 bar) Energy lost in the central dead region (2 cm) : 200 keV (10 bar) and 291 keV (20 bar) => Necessary to correct with vertex reconstruction Low energy (2.7 MeV) will lose 602 keV (10 bar) and 1.4 MeV (20 bar)