Study of compression modes in 56 Ni with the active target MAYA - - PowerPoint PPT Presentation

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Study of compression modes in 56 Ni with the active target MAYA Soumya Bagchi KVI-CART, University of Groningen NUSTAR Annual Meeting 2014 Outline Introduction to Giant Resonances Importance of compression modes in nuclei

SLIDE 1

Study of compression modes in 56Ni with the active target MAYA

Soumya Bagchi

KVI-CART, University of Groningen NUSTAR Annual Meeting 2014

SLIDE 2

Outline

Introduction to Giant Resonances
Importance of compression modes in nuclei
Experimental Setup
Results
Summary and outlook

6th March, 2014 NUSTAR Annual Meeting, GSI | Soumya Bagchi 2

SLIDE 3

Giant Resonances (GR)

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Isovector Out of phase Monopole L = 0 (GMR) Dipole L = 1 (GDR) Isoscalar In phase

Compression modes

SLIDE 4

Giant Resonances (GR)

6th March, 2014 NUSTAR Annual Meeting, GSI | Soumya Bagchi 4

Monopole L = 0 (GMR) Dipole L = 1 (GDR) Isoscalar In phase

Compression modes

[T. Li., et al., PRC 81, 034309 (2010)]

SLIDE 5

Giant Resonances (GR)

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Isovector Out of phase Monopole L = 0 (GMR) Dipole L = 1 (GDR)

Berman and Fultz, Rev. Mod. Phys. 47 (1975) 47

208Pb 120Sn 65Cu

Photo absorption cross sections Isoscalar In phase

Macroscopically:

Excitation Energy
Width

Compression modes

SLIDE 6

Nuclear Incompressibility

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Incompressibility: Measure of the resistance of matter to uniform compression

SLIDE 7

Why study nuclear incompressibility?

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Key input to the EoS of the nuclear matter

EoS of the nuclear matter is important for studying:

Core collapse and supernovae explosion
Formation of neutron star
Collisions of heavy ions

SLIDE 8

Why Ni?

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Incompressibility value (K∞) obtained from isotopic

chain of Pb: 240 ± 10 MeV [G. Colò et al., PRC 70, 024307 (2004)] Sn and Cd: 210 – 215 MeV [T. Li., et al., PRC 81, 034309 (2010)]

[D. Patel., et al., Phys. Lett. B 718 (2012) 447 – 450]

Why is there a discrepancy in K∞ values between Sn/Cd

and Pb?

Need to study for a series of isotopes of a nucleus

SLIDE 9

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58Ni 60Ni 68Ni 56Ni

53Ni

45 ms

54Ni

104 ms

56Ni

6.08 d

55Ni

205 ms

57Ni

35.6 h

58Ni

stable

52Co

115 ms

53Co

242 ms

54Co

193 ms

55Co

17.53 h

56Co

77 d

51Fe

305 ms

52Fe

8.28 h

53Fe

8.51 m

54Fe

stable

α p n

SLIDE 10

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95-97% 56Ni

~ 104 pps 56Ni (α,α’)56Ni*

Primary target 9Be

58Ni 56Ni 54Co 53Fe 55Co 9Be

Primary Beam:

58Ni at 75 MeV/u

Primary Target: 9Be (thickness 500 μm) Secondary Beam:

56Ni at 50 MeV/u

MAYA setup

GANIL Facility

SLIDE 11

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Challenges with exotic beams:

Intensity of exotic beams is very low (~104 – 105 pps)
To get reasonable yields thick target is needed
Very low energy (~ sub MeV) recoil particle will not

come out of the thick target

Active target: Detection takes place at every

point of the target (Detector and target are the same)

Good angular coverage
Effective target thickness can be increased

without much loss of resolution

Detection of very low energy recoil particle is possible

SLIDE 12

Angular distribution: DWBA

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56Ni (α, α’) 56Ni*

SLIDE 13

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Elastic

ISGMR ISGDR

SLIDE 14

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MAYA setup

22 cm

56Ni

500 mbar 95% He and 5% CF4

Edrift

Anode Wire +1300 V Cathode _ 3000 V

SLIDE 15

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MAYA setup

SLIDE 16

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Si/CsI Telescope in MAYA

80 CsI 20 Si Beam 56Ni Recoil He Beam 56Ni Recoil He

SLIDE 17

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ΔE-E detector Beam entrance Mask Cathode pad

SLIDE 18

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Particle Identification in forward ΔE-E telescope

SLIDE 19

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Kinematics reconstruction

Beam 56Ni Recoil He Two dimensional range Bragg Peak Vertex

SLIDE 20

6th March, 2014 NUSTAR Annual Meeting, GSI | Soumya Bagchi 20 Bragg Peak Cathode plane Beam Wires

Kinematics reconstruction

Two dimensional range

SLIDE 21

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t0 tn  Track is going in the upward direction

Bragg Peak Cathode plane

tn > t0 Range Energy

e- Beam Wires

Kinematics reconstruction

Third dimension Two dimensional range Anode wires

SLIDE 22

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Angular Distribution

SLIDE 23

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Excitation energy of 56Ni

Elastic

ISGMR ISGDR

SLIDE 24

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Summary

Compression modes in 56Ni are studied.
Active target has been used to study the compression

modes.

Preliminary results are shown.

Outlook

Excitation energies of the compression modes will be

determined.

Angular distributions of ISGMR and ISGDR will be studied.
Nuclear incompressibility will be measured from the

excitation energies.

SLIDE 25

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