n. saito the rising stopped beam physics meeting technical status of rising at gsi n. saito - gsi...
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N. Saito The RISING stopped beam physics meeting
Technical status of RISING at GSI
N. Saito - GSIfor the RISING collaboration
• Introduction• Detector performance• First results of RISING• Coming experiments
Outline
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Fragment Separator (FRS)
RISING with fast beams
Rare isotope beam + Target
In-beam - spectroscopy
Reaction target ~ 0.5 g/cm2
: ~ 100 MeV/u > 1000 pps
Ge-array
Beam
production target
Degrader
400 – 1000 MeV/u
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
• Secondary fragmentation – With a Be target – Weak inelastic excitation – Population of higher spin
states
• Coulomb excitation – With a Au target – Inelastic excitation
enhanced– One step excitation – Low spin – Excitation to high energy
Type of experiments
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Atomic Background Radiation
Atomic background cross section
To measure - rayabove ~ 400 keV
Beam energy ~ 100 MeV/u
X-rays from target atoms
Radiative electron capture (REC)
Primary Bremsstrahlung (PB)
Secondary Bremsstrahlung (SB)
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
FRagment Separator (FRS)
Dipole magnets : B selection
~ 100 MeV/u
400~1000 MeV/u
MUSIC : Z measurementMulti-wire chambers : Tracking
Fast plastic scintillator : Time of Flight (TOF)
AQ
Be c u
=
Degrader : E
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Identification of beam
Primary beam : 86Kr at 419 MeV/u Fragment setting : 56Cr
CATE
56Cr
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Identification of outgoing particle
CATE-Si • position sensitive• 0.3 mm thick Si • E measurement
CATE-CsI• CsI + PIN diode • Stop beams• E measurement
55Ni + 9Be
108Sn + 197Au
Two-step fragmentation
Coulomb excitation
CAlorimeter TElescope array
ECsI
ESi
ESi
E CsI
Si
CsI 5cm
5cm
E vs E ZZ
E + E AA
Z ~ 0.7
A < 1
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
p
MW MW CATE
Si CsITarget
x
y
Beam spot reconstruction on the target
x
y
Outgoing particle distribution on CATE
Tracking of incoming & outgoing particles
CATE-Si pos. res. ~ 5 mmopening angle ± 3°
MW pos. res. ~ 1 mm
Event-by-event Doppler correction
Impact parameters
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
RISING Ge-array
• 15 EUROBALL cluster detectors
• Clusters at forward angle• Large Lorentz boost (~0.4) • Optimum Doppler shift correction • Minimizing Doppler broadening
• Ring1 at 15.9° 70 cm• Ring2 at 33.0° 70 - 140 cm• Ring3 at 36.0° 70 - 140 cm
• Design (100MeV/u,1.3MeV -ray )• Option 1 : high resolution
• E = 1.0 % (FWHM)• = 1.5 %
• Option 2 : closest geometry• E = 1.6 % (FWHM)• = 2.8 %
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
RISING detectors
Target : Au or Be
15 EUROBALL cluster Ge detectors
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
RISING detectors
• HECTOR array : 8 BaF2 detectors. • For GDR experiments. • Time resolution : ~1 ns. • Background study.
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
First accepted proposalsNo. Nuclei of Interest Primary Beam Spokespersons Experiment Type Accepted
Request (days)
1(S244)
34/36Mg 48Ca P. Mayet2 step fragmentation
lifetime6
245Cr,53Ni,45Sc,
53Mn58Ni M. Bentley 2 step fragmentation 7
3 68Ni 86Kr A. Bracco GDR 7
454Ca, 78Ni ,56Cr 86Kr
H. Grawe,H. Hübel, P.Reiter
Coulex 13
5 88Kr, 90Sr, 86Se 238U D. Tonev Coulex 10
6 102-110Sn, 94-98Ru
124Xe C. Fahlander,M. Górska
Coulex 6
7 132Sn 238U G. de Angelis Knock-out 5
8 132Xe 136Xe A. MajCoulex, Angular
Distr. / Correlations3
9 134Te 136Xe K.-H. Speidel Coulex, g-factor 7
10185,186,187Pb 238U
J. Gerl,A. Andreyev
G.D. Dracoulis
2 step fragmentationlifetime
8
84Kr 84Kr Coulex, Ang. Corr. ~ 78’
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Coulomb excitation of stable 84Kr
84Kr at 113 MeV/u on a 0.4 g/cm2 Au
Conditions for the analysis :• Particle Identification before and after the target• Scattering angle selection 84Kr : 0.5 ~ 2.5 degrees• Selection of one-step Coulomb excitation <M>=1• 84Kr : = 0.396 ( from TOF measurement)
Without D.c. With D.c.
84Kr 2+ 0+
FWHM ~ 1.5 %
Energy [keV] Energy [keV]
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Coulex of radioactive beams
86Kr 419 MeV/u → 56Cr 136 MeV/u on Au 1.0 g/cm2
Preliminary
56Cr 2+->0+
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Two-step fragmentation58Ni 600 MeV/u → 55Ni 171 MeV/u on Be 0.7 g/cm2
NiCoFeMnCr
CaTi
ArS
Si
CATE ECsI
CATEdESi
Preliminary
2+ -> 0+
4+ -> 2+
6+ -> 4+
(8+ -> 6+)
50Cr
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Schedule 2004
May : Two experiments at relativistic energies with HECTOR GDR in 68Ni (A. Bracco) Shell structure at N>>Z nuclei (H. Grawe, H. Hübel, P. Reiter)
Nov/Dec : Experiments at relativistic energies with MINIBALL
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
MINIBALL
Angle 51.3° 86°
Detectors 5 3
Distance 400 mm 400 mm
E 0.36 % 0.37 %
0.82 % 0.36 %
Array E
Clusters 1.0 % 1.5 %
Clusters (70cm) 1.6 % 2.8 %
MINIBALL 0.36 % 1.2%
Total 1.2 % 4.0 %
max = 7.4 % (MINIBALL at ~20cm)
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
2004 May : Experiments at relativistic energies with HECTOR Nov/Dec : Experiments at relativistic energies with MINIBALL
2005 - April : Experiments at relativistic energies with MINIBALL Autumn : Experiments with stopped beams
- -isomer decay - - and -decay- Lifetime measurements in ps~ns with electrical timing methods
2006 Experiments with relativistic beams and stopped beams Feasibility studies for experiments with slowed-down beams
- Multiple Coulomb excitation- One- and two-particle transfer reactions- Fusion and deep inelastic reactions
Schedule
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Two-step fragmentation58Ni 600 MeV/u → 55Ni 171 MeV/u on Be 0.7 g/cm2
NiCoFeMnCr
CaTi
ArS
Si
CATE ECsI
CATEdESi
52Fe 2+ -> 0+
52Fe 4+ -> 2+
Preliminary
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
RISING Ge-array
• 15 EUROBALL cluster detectors • Clusters at forward angle
• Large Lorentz boost (~0.4) • Optimum Doppler shift correction • Minimizing Doppler broadening
•Ring1 at 15.9° 70 cm•Ring2 at 33.0° 70 - 140 cm•Ring3 at 36.0° 70 - 140 cm
•Performances for different distances• Design
• E = 1.0 % (FWHM)• = 1.5 %
• Option : closest geometry• E = 1.6 % (FWHM)• = 2.8 %
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
FRagment Separator (FRS)
Dipole magnets : B selection
Fast plastic scintillator : Time of Flight (TOF)
~ 100 MeV/u
400~1000 MeV/u
MUSIC : Z
Multi-wire chambers : Tracking
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Relativistic Coulomb excitation with the 84Kr primary beam
Scattering angle dependence
2.0-2.5
0.5-1.0
1.5-2.0 2.5-3.0
1.0-1.50.0-0.5
Preliminary
Mainly elastic scattering
Nuclear reactionCoulomb excitationAnalysis by T.Saito
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Two-step fragmentation
Analysis by T.Saito
58Ni 700 MeV/u → 55Ni 171 MeV/u on Be 0.7 g/cm2
29 Mar. 2004N. Saito The RISING stopped beam physics meeting
Two-step fragmentation58Ni 600 MeV/u → 55Ni 171 MeV/u on Be 0.7 g/cm2
NiCoFeMnCr
CaTi
ArS
Si
CATE ECsI
CATEdESi
Preliminary
54Ni 2+ -> 0+
54Ni 4+ -> 2+