S272: Density distribution of Ni and 72Ge from proton...
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S272: Density distribution of 58, 72 Ni and 72 Ge from proton elastic scattering ◆ Spokesperson: Isao Tanihata, Rituparna Kanungo ◆ GSI contact: Chiara Nociforo? ◆ Approved in ~2001 with 60 shifts ◆ Would like to run the experiment either at the end of 2008 or the first half of 2009. ◆ Primary Beams: 86 Kr (500A MeV) 10 10 /pulse 58 Ni (300A MeV) 10 5 /pulse 72 Ge (300A MeV) 10 5 /pulse ◆ Secondary Beam: 72 Ni (300A MeV) ◆ Detector system will be set up at S4 after FRS.
Transcript of S272: Density distribution of Ni and 72Ge from proton...
S272: Density distribution of 58, 72 Ni and 72Ge from proton elastic scattering
◆ Spokesperson: Isao Tanihata, Rituparna Kanungo◆ GSI contact: Chiara Nociforo?◆ Approved in ~2001 with 60 shifts◆ Would like to run the experiment either at the end of
2008 or the first half of 2009.◆ Primary Beams: 86Kr (500A MeV) 1010 /pulse
58Ni (300A MeV) 105 /pulse72Ge (300A MeV) 105 /pulse
◆ Secondary Beam: 72Ni (300A MeV)◆ Detector system will be set up at S4 after FRS.
Density Distribution and EOS◆ The saturation density of nuclear matter is reflected to
the density of nucleus.◆ -> Saturation density of nuclear matter can be
determined from density distributions.◆ -> EOS of asymmetric matter can be studied from
density distribution of neutron rich nuclei.
0
-20
10
density
Bin
ding
Ene
rgy
Den
sity
Distance from center
Difference of EOS between models
◆ Saturation density behaves differently between two typical models. (Skyrme and Relativistic Mean Field)
-20
-10
0
10
0 0.05 0.1 0.15 0 0.05 0.1 0.15 0.2nucleon density [fm-3]
RMFSHF (SIII)
1.0
0.6
0.4
0.2
0
0.8
1.0
0.6
0.4
0.2
0
0.8
nucleon density [fm-3]
Bind
ing
ener
gy p
er n
ucle
on [M
eV] (a)
Two typical equation-of-states
neutron matterneutron matter
stable nucleistable nuclei
The central density gives a guidance to the correct equation of state
rms Radius of Ni isotopes(fm) 5.6
5.4
5.2
5.0
4.8
0
0.100.05
0.15
SIII
RMF
GSI
Central density of Ni isotopes(fm- 3)
SIIIRMF
0.15
0.13
0.14
0.12
2％
10％
20 30 40 50 60
skin thickness of Ni isotopes
SIII
RMF
0.4
0.2
0.0
- 0.2
50％
GSI
GSI
Difference
(fm)
N
Sensitivity of EOS
◆ The effect of the EOS difference is seen in radii, central density, and neutron skin thicknesses.
◆ The difference of radii is not very large.
◆ Densities provide sensitive means to distinguish EOSs.
◆ Skin thicknesses also give very sensitive test (if someone else measures the charge radii).
Measurement to be done
◆ Differential cross section of elastic scattering
65 70 75 80 85 9010-1
100
101
102
103
104
Scat
teri
ng P
roba
bilit
y
Angle of scattered protons
De
ns
ity
Distance from center
Reflects the shape of the nucleus
Radius
Diffuseness
RadiusDiffuseness
Diffraction Pattern
Experimental System
◆ We use two targets, one for ~90° proton (small CM angle scattering) and the other for smaller proton angles.
Last Q at F4
Ion Chamber
Drift ChamberPlasticScintillator
CH2target
NaI(Tl)
solid H2target
22 cm
120 cm
Aramid Foil (20 µm)100 cm SSD
Setup at F4
Ion Chamber
Drift ChamberPlastic
Experimental System (tested at NIRS@Chiba)
BDC
BDCSi-Si(Li)
SHT Beam
NaI(Tl) array
Just photos
Ø = 35 mmd = 1 - 5 mmρd = 8.8 - 44 mg/cm2
beam
recoil
thermal shield
9C preliminary data at Chiba
(p,p)
(p,p’)
θp [deg.(lab.)]
Δθp =1°ε=1
dσ/d
Ω[m
b/Sr
]
Summary
◆ The detector system is ready but we have to transport it to GSI and have to set it up.
◆ It would take two months just for shipping and take several months to set up the system at the location.
◆ We do not have enough electric circuits to keep at GSI for a long time. We would like to borrow standard NIM and CAMAC circuits from GSI as much as possible.
The Collaboration:Osaka U., Miyazaki U. Tohoku U, Tsukuba U, RIKEN, St. Mary U, GSI, U of Bratislava, TU München, KVI
S272: Scheme of S4 setup
Distances and beam sizes [cm]
