First results of the MAGNEX large-acceptance spectrometer

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1 First results of the MAGNEX large-acceptance spectrometer
F.Cappuzzello LEA COLLIGA October 13-15, LNS (Catania) Se si desidera sviluppare più argomenti di discussione, utilizzare più diapositive. Determinare se la propensione degli spettatori consiste nel comprendere un argomento nuovo, apprendere una procedura o approfondire un concetto noto. Sostenere ogni punto con spiegazioni adeguate. Completare la spiegazione con dati tecnici di supporto su stampa oppure su disco, posta elettronica o Internet. Sviluppare ogni punto in modo adeguato per favorire la comunicazione con gli spettatori.

2 The MAGNEX collaboration
 A.Cunsolo, F.Cappuzzello, M.Cavallaro, A.Foti, S.E.A.Orrigo, M.R.D.Rodrigues INFN-LNS, Catania, Italy INFN, Sez. Catania, Catania, Italy Università di Catania, Catania, Italy A.Bonaccorso, T.Borello, P.Guazzoni, H.Lenske, H.Petrascu, C.L.Rodrigues, J.S.Winfield, L.Zetta INFN, Sez. Pisa, Pisa, and Sez. Milano, Milano, Italy University of S. Paulo, IFUSP, Brazil Universitatat Giessen, Giessen, Germany NIPNE, Bucarest, Romania GSI, Darmstadt, Germany Un relatore si trova spesso a dover esporre dati tecnici a un pubblico composto da persone che non conoscono l'argomento o la terminologia specifica. È possibile che l'argomento trattato sia complesso e ricco di dettagli che ne appesantiscono l'esposizione. Per presentare in modo efficace argomenti di questo tipo, seguire le indicazioni fornite da questo modello della Dale Carnegie Training®. Considerare la quantità di tempo a disposizione e organizzare il materiale di conseguenza. Circoscrivere l’argomento da esporre. Suddividere la presentazione in sezioni specifiche. Seguire un ordine logico. Incentrare la spiegazione sull'argomento principale. Chiudere la presentazione con un riepilogo, la ripetizione dei punti chiave o una conclusione logica. Mantenere sempre l’attenzione rivolta agli spettatori, accertandosi che i dati siano chiari e le informazioni rilevanti. Mantenere un livello di argomentazione e terminologia appropriato per gli spettatori. Utilizzare supporti visivi per illustrare i punti chiave. Dimostrare interesse per gli spettatori per conquistarne l’attenzione.

3 Topics The MAGNEX spectrometer Planned experiments
First results from the initial experiments

4 MAGNEX Maximum magnetic rigidity 1.8 T• m Solid angle 51 msr
E max /E min 1.7 Total energy resolution (target 1 mm2) (90% of full acceptance)  1000 Mass resolution 250 Upper bent limits E <30 AMeV 2 < A < 40 E < 25 AMeV 40 < A < 93 A.Cunsolo et al., NIMA 481 (2002) 48 A.Cunsolo et al., NIMA 484 (2002) 56

5 Ray-trace spectrometer
Possible definition: spectrometer based on the solution of the equation of motion of each single detected particle Practically one needs Detailed knowledge of the magnetic field maps Algorithms for high order solution of equation of motion and inversion of transport matrices Detectors to measure positions and angles at the focus V.A.Shchepunov et al., NIMB 204 (2003) 447 A.Lazzaro et al.,I.P.C.S.175 (2005) 171 A.Lazzaro et al., NIMA 570 (2007) 192 A.Cunsolo et al., E.P.J. 150 (2007) 343 A.Lazzaro et al., NIMA 585 (2008) 136 A.Lazzaro et al., NIMA 591 (2008) 394 P.Guazzoni et al., IEEE accepted

6 Initial commissioning
Initial commissioning means a series of tests with different beams and targets with a small scattering chamber Limit of the fixed angle at 255 Limit of the beam energy (10 MV High Voltage on Tandem terminals)

7 Alpha source at the target-object point MAGNEX in large acceptance mode
Counts _foc (rad) X_foc (m) X_foc (m)

8 48Ti + 197Au elastic scattering at 120 MeV
Momentum dispersion 2 measurements of Xfoc with same magnet settings but with 48Ti beam energy changed by 2.6% Result: 3.68 cm/% for K = -0.1 Charge State distribution (diamonds) Agreement with results from INTENSITY calculations (triangles) J.A.Winger et al., Nucl. Instr. Meth. B 70 (1992) 380 Log fraction 100 10-1 10-2 10-3

9 elastic scattering Measure of i via trajectory reconstruction
16O + 58Ni  16O + 58Ni at 80 MeV FWHM  10 mr Consistent with the holes size 16O beam MAGNEX black box Counts Diaphragm (1-mm holes) 58Ni target i (rad) elastic scattering DWBA calculations

10 Experimental lines Spectroscopy of ligth neutron rich nuclei via the CEX reaction (7Li,7Be) at Tandem energies Experiments with quasi stable 14C (18 O) Tandem beams Spectroscopic studies of heavy ions via (p,t) direct 2n pick-up and via (6Li,d) -transfer (next month) 8He spectroscopy via the 7Li(8Li,7Be)8He ( EXCYT beam) at 52 MeV Experiments of nuclear astrophysics (Trojan Horse Method) Experiments with the LNS K800 Superconducting Cyclotron beams (e.g. pionic fusion at subthreshold energies)

11 Ligth neutron rich nuclei Spectroscopy via the (7Li,7Be) CEX reaction
First measurements (December 2007) Targets : AlF3, 27Al and 12C, Final Nuclei : 19O and 27Mg, Beam energy 52 MeV, Data under reduction.

12 PRELIMINARY (~10% statistics)
19F(7Li,7Be)19O at Einc = 52,4 MeV E/E  1000 Lab = 7 19.5 = 50 msr Energy byte =  27% 19.8 keV/ch gs 96 keV 19O PRELIMINARY (~10% statistics) Counts

13 First Experiment (January 2008)
Multi-neutron transfer by 18 O Tandem beams First Experiment (January 2008) Target: 13C 100 g/cm2 Selected reaction channels (18O,17O) (18O,16O) (18O,15O) Reasidual nuclei 14C, 15C and 16C Beam energy 84 MeV, Data under reduction.

14 13C(18O,16O)15C at Einc = 84 MeV Lab = 7 19.5 = 50 msr
Xf (m) Yf (m) 0.74 g.s. 4.22 PRELIMINARY Lab = 7 19.5 = 50 msr Energy byte =  27% Particle identification without TOF Er Residual energy (MeV) Xf (m) 16O 8+ 15O 8+ 17O 8+ 18O 8+ 18O 7+ 18O 6+ PRELIMINARY Not reconstructed focal plane position spectrum

15 Conclusions MAGNEX has successfully started its experimental program (first experiment December 2007). Other two experiments already performed 13C(18O, 16,15O)15,16C on January 2008 and 28Si(7Li,7Be)28Al on July 2008. A new experiment is scheduled next month. The results coming out from data analysis are very encouraging

16 Inversion of transport matrices
f instead of i for MAGNEX Large acceptance condition For MAGNEX up to 11th order ! Differential algebra (Ex:COSY INFINITY) M. Berz et al., PRC 47 (1993) 537 Iterative formula for the inverse matrix

17 The PSD start detector -channel Gassiplex motherboards Pads

18 The FPD detector Trapezoidal geometry
Ion A.Cunsolo et al., NIMA 495 (2002) 216 Trapezoidal geometry Window length 92 cm. Height 20 cm. Depth 16 cm Isobutane pressure between 5 e 50 mbar Energy threshold down to 0.5 MeV/amu No intermediate foils Maximum counting rate 4 kHz

19 Reconstructing trajectories
ANGULAR AND MASS RESOLUTION Angular and mass resolution are ~ ion-independent 6Li + 12C (100 g/cm2) 6Li + 12C (100 g/cm2) ◆ Tm  ~ 38 MeVu ■ 1.06 Tm  ~13 MeVu ▲ Tm  ~ 3 MeV/u

20 Reconstructing trajectories
Energy resolving power for 6Li + 12C (100 g/cm2) A.Lazzaro et al. 7th ICAP, East Lansing, 2002, IOP series 175, pagg LNS Tandem ◆ 1.8 Tm  ~ 38 MeVu a) ■ 1.06 Tm  ~13 MeVu a) ▲ Tm  ~ 3 MeV/u b) ● Tm  8 MeV/u b) LNS – Cyclotron energies LNS - Tandem energies

21 DE [MeV] Eres [MeV] 9Be Z = 3 Z = 2 7Be 1 2 7Li + AlF3 l = 25°  5°
El = 40.2 MeV

22 TOF [msec] xfoc [m] TOF [msec] xfoc [m]
7Li + AlF3, l = 25°  5°, El = 40.2 MeV TOF [msec] 7Be 1 9Be xfoc [m] TOF [msec] 2 7Be xfoc [m]