Vamos Exogam Spectrometer Goals VAMOS was designed for

Vamos + Exogam Spectrometer

Goals VAMOS was designed for spectroscopy studies • using different reaction types • in particular induced by low intensity radioactive beams Advantages Coupling with • large acceptance • variable mode • EXOGAM Main working modes • TIARA, DIAMANT • magnetic spectrometer • INDRA • separator • (Neutron Wall)

VAMOS Spectrometer Schematic View Focal Plane detection DIPOLE Velocity Filter QUADRUPOLES EXOGAM BEAM

VAMOS in reality

Specifications Quadrupoles (850 A) Q 1 Q 2 Magnetic length [m] 0. 6 0. 9 Field gradient [T/m] 7. 0 2. 4 Bρ full(reduced) Ω [Tm] Dipole (850 A) 1. 8 (2. 2) Wien Filter Magnetic field [T] 1. 2 Length [m] 1 Magnetic length [m] 1. 57 Gap [m] 0. 15 Deflection radius [m] 1. 5 E [k. V] 300 Bρ at 60° [Tm] 1. 8 B [T] 0. 2

Specifications Path length 7. 3 m Rotation 0°-90° Solid angle 100 msr Translation 0. 4 -1. 2 m Momentum ± 7 % Focal Plane Dispersion 2. 5 cm/% Angle Example: Θ : -100, +100 [mrad] Bρ : (0. 97, 1, 1. 03)BNc 0°-60°

Light/Fast Ion Detection Dispersive Plane Drift Chamber X: charge distribution 2 x 64 pads (6. 3 x 50) mm XFWHM ~200 μm Y: drift time YFWHM ~ 500 μm Ionisation Chamber 2 x 7 pads (50 x 50) mm 1 x 7 pads (50 x 170)mm Plastic Detector ΔEFWHM ~ 3% EFWHM ~ 4% Silicon Wall

Heavy/Slow Ion Detection Ionisation Chamber Secondary electron Detector Mylar emissive foil Se-D XFWHM ~ 1 mm YFWHM ~ 2 mm TFWHM ~ 300 ps

VAMOS Measurement Xf Y f θf φ f Bρ θ Resolution φ M/q TOF V q M M/q ~ Bρ x TOF M ~ E x TOF 2 Z 2 ~ E x ΔE ~ ΔE/TOF 2 E Z ΔE Θ 0. 1° Φ 0. 3° Bρ 0. 5% M/q 0. 5% q 1/30 M 1/200 Z 1/30

EXOGAM 12 closely packed Compton suppressed Ge segmented clover detectors Efficiency ~ 12% at 1. 33 Me. V

Deep Inelastic Collisions measured with VAMOS d. E vs E

Deep Inelastic Collisions measured with VAMOS M vs M/Q

Search for 2+ in 54 Ca magicity at N=34 0 -5 f 5/2 p 1/2 p 3/2 54 Ca Large experimental effort to 48 Ca -10 f 7/2 Pronounced shell gap in 54 Ca estimate this gap from studies of nearby nuclei. Direct information on this gap is the 2+ energy.

Identification spectra d. E vs E M vs M/Q

Spectra of 50 Ca γ-γ projection γ-γ gate

Spectra of 52 Ca

Recoil (Decay) Tagging Reaction: 18 O@95 Me. V Set. Up: EXOGAM VAMOS + 208 Pb -> 222 Th + 4 n Time stamping: Time correlations measured using the universal clock CENTRUM • at 0º with focal plane at 10º using WIEN filter • focal plane detection: Se. D, Si. Wall

Recoil Decay Tagging