1. Exotica in Terra Incognita
Saha
Institute of
Nuclear
Physics,
Kolkata
C. Samanta
April 8, 2003
IPR, India

2. Plan Of The Talk Origin of the elements in the universe
Nuclei in uncharted territory
How to make them
Who are making them
What we know about them, so far
Exotic structures
New Modes of Oscillation
Curious decay preferences
New magicity
Applications in different branches of Physics
April 8, 2003
IPR, India

3. April 8, 2003
IPR, India

4. Nucleosynthesis of the light elements
Beyond 56Fe, fusion reactions do not release energy
April 8, 2003
IPR, India

5. Nuclear Chart
April 8, 2003
IPR, India

6. Normal Stable Nuclei
Radius = 1.2 A1/3 A = Total number of neutrons and protons in the nucleus rn
Density rp
A=3
A=7
A=17
Radius (fm)
Number of protons and neutrons are balanced: N/Z = 1 – 1.5 Separation energy of a nucleon is constant: Es = 6 – 8 MeV Nucleon density distributions are similar: ro = 0.15 fm-3 Protons and neutrons are homogeneously mixed: rn/rp  N/Z
April 8, 2003
IPR, India

7. Halo Nucleus 11Li: Good Bye to Old Concepts!
Radius ≠ 1.2 A1/3 rn / rp ≠ N / Z
Normal Stable Nucleus
April 8, 2003
IPR, India

8. Borromean Nuclei 11Li = 9Li +n+n 11Li-n 10Li Does not exist!
6He=4He+n+n
6He-n 5He Does not exist!
Heraldic emblem of the medieval
princes of Borromeo, Italy
April 8, 2003
IPR, India

9. Schematic Diagram of Density Distributions in Normal, Skin and Halo Nucleirn
NORMAL rp
Density
rn-rp=0
Radius (r)
SKIN
HALO rn rn rp rp
Radius (r)
rn-rp > 0
Radius (r)
rn-rp >> 0
April 8, 2003
IPR, India

10. What is an exotic nucleus?
Normal Nucleus:
Exotic Nucleus:
12C (carbon)
6 protons
+ 6 neutrons
Stable, found in nature
22C (carbon)
6 protons +
16 neutrons
Radioactive, at the limit of nuclear binding
Characteristics of exotic nuclei: Excess of neutrons or protons, short half-life, neutron or proton dominated surface, low separation energy
April 8, 2003
IPR, India

11. Rare Isotopes Away from the line of stabilities; 0.6 < N/Z < 4
Short lived; sec < t1/2 < few seconds
Low nucleon separation Energy; Es << 8 MeV
Large radius ; r >> 1.2 A-1/3
(Ground state being close to continuum  Quantum tunneling)
Exotic properties; skin, halo, large core, …..?
April 8, 2003
IPR, India

12. How to make these rare isotopes?
Transfer reactions (light nuclei)
Fusion-evaporation (proton dripline)
Fission (neutron dripline)
Fragmentation
Target fragmentation
Projectile fragmentation
April 8, 2003
IPR, India

13. Transfer Reactions
April 8, 2003
IPR, India

14. Fusion Evaporation 292 MeV 54Fe + 92Mo  146Er(p4n)141Ho
402 MeV 78Kr + 58Ni  136Gd(p4n)131Eu
A.A. Sonzogni et al., Phys. Rev. Lett (1999)
D. Seweryniak et al., Phys. Rev. Lett (2001)
April 8, 2003
IPR, India

15. Fission
K.H. Schmidt et al., Model predictions of the fission-product yields for 238U (2001)
April 8, 2003
IPR, India

16. Target Fragmentation
Random removal of protons and neutrons from heavy target nuclei by energetic light projectiles (pre-equilibrium and equilibrium emissions).
April 8, 2003
IPR, India

17. Projectile Fragmentation
Random removal of protons and neutrons from heavy projectile in
peripheral collisions
hot participant zone
projectile fragment
projectile
target
Cooling by evaporation.
projectile fragment
April 8, 2003
IPR, India

18. Techniques 1) ISOL 2) Fragmentation 3) Reactors p,d,t,… heavy ions
high energy beam
RIB
(low energy)
Accelerator,
Storage,….
Thick target
2) Fragmentation
High energy
heavy ion beam
RIB
(high energy)
Spectrometers,…
Target
3) Reactors
Fission products
(neutral,
1+charge state)
Thermal
neutrons
RIB
(low energy)
Accelerator,
Storage,….
Thin fissile target
High charge state
breeder
April 8, 2003
IPR, India

19. Definitions/Numbers 1pnA, 80 MeV/nucleon, 18O, 8+ Energy
Energy per nucleon: MeV
Total energy (80 A): MeV
Momentum: MeV/c
Velocity: cm/ns
0.39 c
Rigidity: (p/q) Tm
Beam Intensity
Particle Current: pnA
Electrical Current: enA
Particles: x109/s
Power: W
April 8, 2003
IPR, India

20. April 8, 2003
IPR, India

21. New physics from Rare Isotopes
Exotic shapes
New Magicity
New modes of oscillation
New modes of decay
New stability island beyond the sea of instability
April 8, 2003
IPR, India

22. Proton halo Neutron halo Nuclei Nuclei 8B (1p) 6He (2n)
17F (1p, 1st ex st) Li (2n)
17Ne (2p) Be (1n), 14Be (2n)
23Al (1p) B (2n)
19C (1n)
April 8, 2003
IPR, India

23. We would not exist! Magicity Atomic Magic Numbers : 2, 10, 18, 36 ….
Inert gases: He (Z=2), Ne (Z=10), Ar (Z=18), Kr (Z=36)
Nuclear Magic Numbers: 2, 8, 20, 28, 50, 82…
Abundant He(Z=2), O(Z=8), Ca(Z=20), Ni(Z=28), Sn (Z=50), Pb(Z=82)
What would have happened if the magic numbers were the same?
We would not exist!
April 8, 2003
IPR, India

24. Shell Model & Nuclear Magic Numbers
April 8, 2003
IPR, India

25. New Magicity in Nuclei Loss of magicity:
Experiment: [PRL 85, 266 (2000)]
N=8 (Z=4), N=20 (Z=12)
Theory:
N=82 (Z< 48) Z=82 (N~107)
C.Samanta and S.Adhikari, Phys. Rev. C 65, (2002)
C. Samanta, Jour. Heavy Ion Phys (in press)
April 8, 2003
IPR, India

26. Novel Structure
Enlarged Core – rapid movement of nuclear shells in nuclei away from the line of stability gives rise to new shell closure at N=16.
Experimental Evidence of Core Modification in the Near Drip-Line Nucleus 23O,
Rituparna Kanungo et al.,
Phys. Rev. Lett.88, (2002)
Current Science News Headlines
March/topic shtm
April 8, 2003
IPR, India

27. April 8, 2003
IPR, India

28. Modes of Oscillations Giant Pygmy S t r e n g h Excitation Energy
April 8, 2003
IPR, India

29. Is the 1.3 MeV excited state of 11Li a signature of pygmy resonance?
R. Kanungo and C. Samanta, Jour. Phys. G: Nucl. Part. Phys.24, 1611(1998)
April 8, 2003
IPR, India

30. Resonance or, Non-resonance Breakup?
D. Gupta et al, Nucl. Phys. A 683,3 ( 2001); Hottest Paper in NPA
April 8, 2003
IPR, India

31. b-stable nuclei V(r) b+ b- r protons neutrons n drip line nuclei V(r)
p drip line nuclei V(r) r r b- b+
protons
neutrons
protons
neutrons
April 8, 2003
IPR, India

32. Two Proton Decay – a new mode of decay!
Researchers have monitored Ne-18 decay through one of the modes illustrated above. They believe they have finally detected the elusive dual-proton (He-2)decay, rather than democratic emission. The third mode, sequential proton emission, is not possible for the excited state of neon formed in a recent Oak Ridge National Laboratory experiment.
Reported by: J. Gómez del Campo et al, Physics Review Letters, 1 January, 2000.
April 8, 2003
IPR, India

33. April 8, 2003
IPR, India

34. Heavy Nuclei Element Year Place
106 (Seaborgium) LBL, USA & JINR, Dubna
107 (bohrium) GSI, Darmstadt, Germany
108 (hassium), GSI
109 (meitnerium) GSI
110 (ununnilium) GSI (A=269)
111 (unununium) GSI
112 (ununbium) GSI (30 x 10-6 s) (ununtrium) (Not made yet)
114 (ununquadium) FLNR (N=184 not reached)
115 (ununpentium) (Not made yet)
116 (ununhexium) FLNR
April 8, 2003
IPR, India

35. a-decay chain to identify SHE
April 8, 2003
IPR, India

36. Where is SHE? Production of longer lived neutron rich isotopes
Connection to newly synthesized elements
April 8, 2003
IPR, India

37. Application of Rare Isotopes
Nuclear Physics
Astrophysics
Surface Science
Medicine
April 8, 2003
IPR, India

38. An illustration of how radioactive probe atoms implanted in a solid can act as "spies" on their microscopic environment. The properties of the probe atom are modified by the local microscopic environment and that information is carried away by the radiation emitted in the radioactive decay that follows.
April 8, 2003
IPR, India

39. Medical Application
Combining an RI beam and the PET allows simultaneous diagnosis and treatment of cancers. A test experiment of this combination using a 11C beam demonstrates that the beam irradiation is possible while monitoring the stopping location inside an object within a few mm accuracys. This technique is expected to be applicable to other medical fields than the cancer treatment and to fields other than medicine in the future.
April 8, 2003
IPR, India

40. Upcoming RIB Facilities - Worldwide
RIKEN (Japan)
Cyclotron – MeV/u
Multi-Storage Rings
Status: Phase I construction started
RIA (USA)
Superconducting Linac – 400 MeV/u
Isol/In-Flight hybrid; no storage rings
Status: Proposed (NSAC priority)
GSI project:
High Energy (1.5 GeV/u) Luminosity, Purity, Efficiency
Synchroton <=> Storage Rings optimal choice!!
April 8, 2003
IPR, India

41. T H A N K Y O U
April 8, 2003
IPR, India

42. April 8, 2003
IPR, India

43. Nucleosynthesis of the light elements
Prior to about one second after the Big Bang, matter - in the form of free neutrons and protons - was very hot and dense.
As the Universe expanded, the temperature fell and some of these nucleons were synthesised into the light elements: deuterium (D), helium-3, and helium-4. Theoretical calculations for these nuclear processes predict, for example, that about a quarter of the Universe consists of helium-4, a result which is in good agreement with current stellar observations.
The heavier elements, of which we are partly made, were created later in the interiors of stars and spread widely in supernova explosions.
April 8, 2003
IPR, India

44. Borromean Heraldic emblem of the medieval princes of Borromeo, Italy
4He, 6He, 8He, 10He exist, but 5He, 7He, 9He do not.
11Li, 9Li exist but 10Li does not.
April 8, 2003
IPR, India

45. Rare Isotopes Away from the line of stabilities; 0.6 < N/Z < 4
Short lived; sec < t1/2 < few seconds
Low nucleon separation Energy; Es << 8 MeV
Quantum tunneling effect; r > ro A-1/3
Exotic properties; skin, halo, large core, …..?
April 8, 2003
IPR, India

46. THE HOT BIG BANG MODEL
About ten billion years ago, the Universe began in a gigantic explosion - the Hot Big Bang!
Its subsequent evolution from one hundredth of a second upto the present day can be reliably described by the Big Bang model. This includes the expansion of the Universe, the origin of light elements and the relic radiation from the initial fire all , as well as a framework for understanding the formation of galaxies and other large-scale structures. In fact, the Big Bang model is now so well-attested that it is known as the
standard cosmology.
April 8, 2003
IPR, India

47. April 8, 2003
IPR, India

48. April 8, 2003
IPR, India

49. 106 (Seaborgium) 1974 Lawrence-Berkeley Laboratory, USA
Element Year Place
106 (Seaborgium) Lawrence-Berkeley Laboratory, USA
Joint Institute for Nuclear Research,
Dubna,Moscow
107 (bohrium), Gesellschaft für Schwerionenforschung
108 (hassium),
109 (meitnerium) (GSI), Darmstadt, Germany
110 (ununnilium) (A=269)
111 (unununium)
112 (ununbium) (30 x 10-6 s)
113 (ununtrium) (NOT MADE YET)
Finally near the sea- shore of where SHE (Z = 114, N= 184) Lives
114 (ununquadium) Flerov Laboratory of Nuclear Reactions,
(30 Seconds) JINR(US-Russia Joint Venture) Pu-244
supplied by LBNL. Dubna made two
isotopes of the element, one had 175
neutrons, the other had 173 neutrons,
N=184 not reached yet
115 (ununpentium) (NOT MADE YET)
116 (ununhexium) Flerov Laboratory of Nuclear Reactions,
JINR
117 (ununseptium) (NOT MADE YET)
(ununoctium) Lawrence Berkeley National
Laboratory Laboratory in California
On July 27, 2001, results retracted (Physical Review Letters)
April 8, 2003
IPR, India

50. Giant Dipole Resonance, Soft-Dipole Resonance and Spin Dipole Resonance
April 8, 2003
IPR, India

51. Neutron Halo/Skin Nuclei
April 8, 2003
IPR, India

52. Isospin Tz = (N-Z)/2 Neutron rich Proton rich
A = 21 A 21 C 6 15 Z N 21 21 21 21 21 21 21 21 C N O F Ne Na Mg Al 6 15 7 14 8 13 9 12 10 11 11 10 12 9 13 8 T Z
+9/ / / / /2 –1/2 –3/2 –5/2
Neutron rich
Proton rich
April 8, 2003
IPR, India

53. New Magicity in Nuclei Loss of magicity:
Experiment: [PRL 85, 266 (2000)]
N=8 (Z=4), N=20 (Z=12)
Theory:
N=82 (Z< 48) Z=82 (N~107)
C.Samanta and S.Adhikari, Phys. Rev. C 65, (2002) T.Otsuka et al., Phys. Rev. Lett. 87, (2001) A. Ozawa et. al., Phys. Rev. Lett. 84, 5493 (2000)
April 8, 2003
IPR, India