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Low-q measurements to look at bulk properties

FUSTIPEN Topical Meeting on

« New Directions for Nuclear Structure and Reaction Theories »

Caen, France

March 18, 2015

Nasser Kalantar-Nayestanaki, KVI-CART, University of Groningen

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Bulk Properties

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Example:The Collective Response of the Nucleus: Giant Resonances

IsovectorIsoscalar

Monopole (GMR)

Dipole(GDR)

Quadrupole (GQR) B

erm

an a

nd

Fu

lz, R

ev. M

od

. Ph

ys. 4

7 (1

975)

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208Pb

120Sn

65Cu

Photo-neutron cross sections

Electric giant resonances

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Collective oscillations of all neutrons and all protons in a nucleus in phase (isoscalar) or out of phase (isovector)

Breathing Mode Squeezing Mode No Density VariationShape ChangeM. Itoh

ISGMRISGMR ISGDRISGDR ISGQRISGQR

Giant Resonance

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M. Itoh

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Nucleus Many-body system with a finite size

Vibrations Multipole expansion with r, Ylm , t, s

S=0, T=0 S=0, T=1S=0, T=1 S=1, T=1 S=1, T=1

L=0: Monopole

L=1: Dipole

L=2: Quadrupole

L=3: Octupole

ISGMR IVGMRIAS GTR IVSGMR

LEOR, HEOR

r2Y0 tY0

ISGQR

ISGDR IVGDR IVSGDR

t r2Y0 t Y0 t r2Y0

r3Y1 t rY1 t rY1

r2Y2

IVGQR

t r2Y2 t r2Y2

r3Y3

IVSGQR

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Incompressibility or bulk modulus (K) is a measure of substance’s resistance to uniform compression and can be defined as

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Investigation of Nuclear Matter Distributions along Isotopic Chains:

halo, skin structure

probe in-medium interactions at extreme isospin (almost pure neutron

matter)

in combination with electron scattering (ELISe project @ FAIR):

separate neutron/proton content of nuclear matter (deduce neutron skins)

method: elastic proton scattering at low q: high sensitivity to nuclear periphery

Why low momentum transfers hadronic scattering?

Investigation of Giant Monopole Resonance in Doubly Magic Nuclei:

gives access to nuclear compressibility key parameters of the EOS

new collective modes (breathing mode of neutron skin)

method: inelastic scattering at low q

Investigation of Gamow-Teller Transitions: weak interaction rates for N = Z waiting point nuclei in the rp-process

electron capture rates in the pre-supernova evolution (core collapse)

method: (3He,t), (d,2He) charge exchange reactions at low q

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Kinematics for collision of protons with exotic nuclei (with fixed heavy/light target)

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Kinematics for inverse reaction for 56Ni

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Advantages and disadvantages of storage-ring experiments

Advantages:Large intensities in the ringLittle energy loss in the targetNo target window (no background)High resolution of the beam (cooling)Forward focusing for high-energy particlesLow energy threshold

Disadvantages:Ultra high vacuumVery small recoil energies for low qThin targets

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Advantages and disadvantages of active targets

Advantages:Large target thickness (without “limits”)Good angular coverageNo target window (no background)Forward focusing for high-energy particlesLow energy threshold

Disadvantages:Very small recoil energies for low qLow beam intensities

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R3B (external tar.) vs. EXL (ring exp.)External target (thick)

Low beam current

High-energy particles

Large momentum transfer

Target contamination

Quasi-elastic scattering

Internal target (thin)

High beam current

Low-energy particles

Small momentum transfer

No target window

Giant resonances

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CR

Super FRS

NESR

ESR

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The EXL Experiment @ FAIR

Details of the EXL setup

Design goals: Universality: applicable to a wide class of reactions Good energy and angular resolution Large solid angle acceptance Specially dedicated for low q measurements with high luminosity (> 1028 cm-2 s-1)

Detection systems for: Target recoils and gammas (p,α,n,γ) Forward ejectiles (p,n) Beam-like heavy ions

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First experiments with the existing ring at GSI (ESR)

Exotic nuclei studied in storage rings

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CR

Super FRS

NESR

ESR

Exotic nuclei studied in storage rings

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Setup @ ESR ring

Exotic nuclei studied in storage rings

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The new ESR Scattering chamber

beam

target

2nd DSSD

1st DSSD& Si(Li)s

aperture

Si(Li)

DSSD

● DSSD: 128×64 strips, (6×6) cm², 285 µm thick

● Si(Li): 8 pads, (8×4) cm², 6.5 mm thick

● active vacuum barrier● moveable aperture to

improve angular resolution

Exotic nuclei studied in storage rings

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Exotic nuclei studied in storage rings

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Beam current

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Target density

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Reaction: 56Ni(p,p’)56Ni* or 56Ni(α,α’)56Ni*

53Ni 45 ms

54Ni104 ms

55Ni205 ms

56Ni 6.08 d

57Ni 35.6 h

52Co115 ms

51Fe305 ms

53Co242 ms

52Fe8.28 h

53Fe8.51 m

54Co193 ms

55Co17.53 h

56Co 77 d

54Fe stable

58Ni stable

The choice of the Nucleus

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Kinematics for inverse reaction for 56Ni

Exotic nuclei studied in storage rings

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First results with radioactive beam

Exotic nuclei studied in storage rings

October 25, 2012:

First Nuclear Reaction Experiment with Stored Radioactive Beam!!!!

Beam energy 400 MeV/u

56Ni (p,p)

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Exotic nuclei studied in storage rings

Preliminary

DSSD

1st Si(Li)

2nd Si(Li)

beamtarget

56Ni(p,p), E = 400 MeV/u

First results with radioactive beam

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First results with radioactive beam

Preliminary

56Ni(p,p`), E = 400 MeV/u Identification of Inelastic Scattering

56Ni (p,p)

56Ni (p,p`)1. excited state at 2.7 MeV

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Exotic nuclei studied in storage rings

First results with radioactive beam

Preliminary

M. v. Schmid 56Ni(p,p), E = 400 MeV/u Angular Distribution

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Exotic nuclei studied in storage rings

First results with radioactive beam

Preliminary

56Ni(p,p), E = 400 MeV/u Angular Distribution M. v. Schmid

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• Elastic p-scattering off 56Ni (E105)

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preliminary!

First results with radioactive beam

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• Elastic p-scattering off 56Ni and 58Ni (E105)

First results with radioactive beam

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• Elastic p-scattering off 56Ni and 58Ni (E105)

First results with radioactive beam

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First results with radioactive beam • Elastic p-scattering off 56Ni and 58Ni (E105)

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Inelastic scattering

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First results with radioactive beam

• Inelastic scattering of alphas from 58Ni (E105)

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95-97% 56Ni ~ 104 pps

56Ni (α,α’)56Ni*

Primary target 9Be

58Ni56Ni54Co

53Fe55Co

9Be

Primary Beam: 58Ni at 75 MeV/u

Primary Target: 9Be (thickness 525.6 μm)

Secondary Beam: 56Ni at 50 MeV/u

MAYA setup

GANIL Facility

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Schematic view of MAYA active target detector

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Mask

Gassiplex Chips

Inside MAYA

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Anode Wires

Cathode pad in MAYA

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80 CsI Detectors

20 Si Detectors

Diamond Detector

ΔE-E telescope in MAYA

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Particle identification in Si/ScI detectors

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Recoil Track

Vertex

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Range extraction of recoil track

Range of recoil alpha particle

Maximum Amplitude

Maximum Amplitude / 2

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Excitation energy of 56Ni

Elastic peak

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Excitation energy of 56Ni at θCM=5.5o

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Low-lying dipole mode in 56Ni

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Monopole mode in 56Ni

56Ni (d, d’) 56Ni*

C. Monrozeau et al., PRL 100 (2008) 042501

This work:56Ni (α,α’) 56Ni*

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Monopole mode in 56Ni: ring vs. active target

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Conclusions and outlook• Large efforts are taking place for both the ring

environments as well as for active targets. • Bulk properties (radius, compressibility etc.) are the

main subject of the low-q measurements. • The goal is to go towards the medium heavy and

heavy nuclei (astrophysical processes). • First measurements done with Ni isotopes. • First physics measurements are already producing

beautiful results.• More measurements are planned for both systems.

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Upgrade of the first EXL experiment

Exotic nuclei studied in storage rings

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The EXL-E105 Collaboration

S. Bagchi1, S. Bönig2, M. Castlós3, I. Dillmann4, C. Dimopoulou4, P. Egelhof4, V. Eremin5, H. Geissel4, R. Gernhäuser6, M.N. Harakeh1, A.-L. Hartig2, S. Ilieva2, N. Kalantar‑Nayestanaki1,

O. Kiselev4, H. Kollmus4, C. Kozhuharov4, A. Krasznahorkay3, T. Kröll2, M. Kuilman1, S. Litvinov4, Yu.A. Litvinov4, M. Mahjour-Shafiei1, M. Mutterer4, D. Nagae8, M.A. Najafi1, C. Nociforo4,

F. Nolden4, U. Popp4, C. Rigollet1, S. Roy1, C. Scheidenberger4, M. von Schmid2, M. Steck4, B. Streicher2,4, L. Stuhl3, M. Takechi4, M. Thürauf2, T. Uesaka9, H. Weick4, J.S. Winfield4,

D. Winters4, P.J. Woods10, T. Yamaguchi11, K. Yue4,7, J.C. Zamora2, J. Zenihiro9

1 KVI, Groningen2 Technische Universität Darmstadt

3 ATOMKI, Debrecen4 GSI, Darmstadt

5 Ioffe Physico-Technical Institute, St.Petersburg6 Technische Universität München

7 Institute of Modern Physics, Lanzhou8 University of Tsukuba9 RIKEN Nishina Center

10 The University of Edinburgh11 Saitama University

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Thank you!