Concettina Sfienti, GSI Darmstadt

Concettina Sfienti

Concettina Sfienti, GSI Darmstadt

Isotopic Effects in Spectator Fragmentation at Relativistic Energies

Gross Features and Isotopic Effects

Limiting Temperature

Isoscaling and the Symmetry Energy

Conclusion & Outlook

The ALADiN Recipe

Physics Motivation

NUFRA2007International Conference on Nuclear Fragmentation From Basic Research to ApplicationsSeptember 24 - October 1, 2007, Kemer (Antalya)

Concettina Sfienti

S.BianchinS.Bianchin, K.Kezzar, , K.Kezzar, A.Le FèvreA.Le Fèvre, J.Lühning , J.Lühning J.LukasikJ.Lukasik, U.Lynen, W.F.J. Müller, H.Orth, A.N.Otte, , U.Lynen, W.F.J. Müller, H.Orth, A.N.Otte,

H.Sann, H.Sann, C.SfientiC.Sfienti, C.Schwarz, A.Sokolov, , C.Schwarz, A.Sokolov, W.TrautmannW.Trautmann, J. Wiechula, M.Hellström, D.Henzlova, , J. Wiechula, M.Hellström, D.Henzlova,

K.Sümmerer, H.Weick, P.Adrich, T.Aumann, K.Sümmerer, H.Weick, P.Adrich, T.Aumann, H.Emling, Y.Leifels, R.Palit, H.Simon, H.Johansson, H.Emling, Y.Leifels, R.Palit, H.Simon, H.Johansson,

M.De NapoliM.De Napoli, G.Imme', G.Raciti, E.Rapisarda, , G.Imme', G.Raciti, E.Rapisarda, R.Bassini, C.Boiano,I.Iori, A.Pullia,R.Bassini, C.Boiano,I.Iori, A.Pullia, W.G.Lynch, W.G.Lynch,

M.Mocko, M.B.Tsang, M.Wallace, C.O.Bacri, M.Mocko, M.B.Tsang, M.Wallace, C.O.Bacri, A.Boudard, J-E.Ducret, A. Lafriakh, E.Le Gentil, A.Boudard, J-E.Ducret, A. Lafriakh, E.Le Gentil,

C.Volant, T. Barczyk, C.Volant, T. Barczyk, J.BrzychczykJ.Brzychczyk, J.Cibor, Z.Majka, , J.Cibor, Z.Majka, A.Mykulyak, A.Mykulyak, P.PawlowskiP.Pawlowski, A.Wieloch, B. Zwieglinski, , A.Wieloch, B. Zwieglinski,

B.Czech and B.Czech and A.S.BotvinaA.S.Botvina

Concettina Sfienti

… … study nuclear matter under extreme conditions of study nuclear matter under extreme conditions of density (high and low), temperature, size , isospin…density (high and low), temperature, size , isospin…

… … study nuclear matter under extreme conditions of study nuclear matter under extreme conditions of density (high and low), temperature, size , isospin…density (high and low), temperature, size , isospin…

Spectators can be heated !

Advantages of the Recipe

Typical Incident Energy 1 AGeV

(almost) no flow

Source well localized in rapidity

Equilibrated System

Easy 4 coverage for fragments

Disadvantages of the Recipe

Varying Size of the system by varying Excitation Energy.

Disadvantages: Typical Incident Energy 30AMeV Flowcentralcollision 0 Overlap Participant & Spectators

Physics Motivation

Concettina Sfienti

The ALADiN Program

UNIVERSALITY of Spectator Fragmentation

Physics Motivation

Concettina Sfienti

The ALADiN Caloric Curve

J. Besprosvany and S. Levit Phys. Lett B 217 (1989) 1

Proton rich nuclei: vanishing limiting temperatures

J.B. Natowitz et al., Phys.Rev. C 65 034618 (2002)

Physics Motivation

Concettina Sfienti

The ALADiN Spectrometer

HodoCHodoCTT

ALADiALADiN N MagneMagnett

TP-MUSIC TP-MUSIC IIIIII

TOF-TOF-WallWall

LANDLAND

TargetTarget

ALL Fragments (Z 2)

Isotope Resolution Protons...(but TOF)

124Sn,197Au,124La,107Sn

Einc = 600AMeV ( 1000 p/sec)

Secondary Beams Secondary Beams (Low Intensities!)(Low Intensities!)

The ALADiN Recipe

Concettina SfientiThe ALADiN Recipe

The ALADiN Spectrometer

0

213.0

m

ZR

A

Concettina SfientiGross Features and Isotopic Effects

124Sn

124La

107Sn

First N/Z Effects on Mass Spectra

Discriminant analysisJ. Łukasik et al., arXiv:0707.0598

Concettina Sfienti

Charge Partition


Searching for N/Z effects in...

N/Z of light-mass fragmentsIsotopic RatiosNeutron Emission

Concettina SfientiGross Features and Isotopic Effects

N/Z Effects on Charge Partition

At low excitation energy neutron emission of

heavy residue suppressed for the

neutron-poor systems

Concettina Sfienti

ZZ )(

Properties of Hot Fragments


Concettina Sfienti

R. Ogul and A.S. Botvina, PRC (2002)

B0 = 18 MeV


Isotopic Inversion of Properties of Hot Fragments: the Surface term

Concettina Sfienti

A.S. Botvina et al., nucl-th/0606060

centrality

B = aV · A - aO · A2/3 - aC · Z2/A1/3 - aS · (A-2Z)2 / A + aP· δ / A1/2


N/Z Dependence of the Surface Term

Concettina Sfienti

● ● ● SMM ensemble calculations for γ=14, preliminary

neutron initial(N/Z) projectile

(by P.Pawlowski)


N/Z Effects on Neutrons Multiplicities

Concettina Sfienti

238U

56Fe

FRS data

FRS data

W.Trautmann, NN2006

124Sn

107Sn 238U124Sn

56Fe

107Sn

close to expectation for hot fragments

Z=8

Odd-Even Effects Structure effects Memory Effects They may cancel in scaling plots

Odd-Even Effects larger for the proton-rich systems Strongly bound even-even nuclei attract a large fraction of the product yield in the secondary stage


Light Fragments (inclusive)

Concettina Sfienti

Odd-even effects


Weak dependence on centrality

N. Buyukcizmeci et al, EPJA (2005)

Concettina Sfienti

Comparison with SMM


Concettina SfientiLimiting Temperature

N/Z on Isotopic Ratios

extra yield in neutron poor case

Concettina SfientiLimiting Temperature

N/Z on Isotopic Temperatures

SmallSmall

Smallsmall

smallsmall

effects

Small

smallsmall

small

Concettina Sfienti

Isoscaling

Isoscaling and the Symmetry Energy

«systematic behavior of yield ratios following grandcanonical expectations»

T

)exp()()exp(),(

),(),(

p

1

212

T

ZNSZNCZNY

ZNYZNR

n

M.B. Tsang et al., PRC 64, 054615 (2001) M.B.Tsang et al. PRL123(2001)

Concettina SfientiIsoscaling and the Symmetry Energy

Isoscaling


…from isoscaling to

22

22

21

214

A

Z

A

Z

Tn

p0 fit of individual Z fits

First experimental conclusion:The individual slopes are identical for Z≥3

Second experimental conclusion:The Isoscaling parameters continue to drop

Increase

in te

mpera

ture

does not c

ompensa

te

decrease

of


Comparison with existing data….

A. Le Fevre et al., PRL 94(2005) 162701

D.V. Shetty et al.,

PRC 76(2007) 024606

Concettina Sfienti

22

22

21

214

A

Z

A

Z

Tn

Discussion (I)

S.Albergo et al. Il Nuovo Cimento A (1985)

T

Decrease in confirmed Apparent Saturation could depend on T


22

22

21

214

A

Z

A

Z

Tn

Discussion (II)

22

22

21

21

A

Z

A

Z

A. Le Fèvre et al., PRL 94, 162701 (2005)

Concettina Sfienti

In the grand-canonical approximation:

22

22

21

21

2

1

21

2

1

4ln

expexpexp

A

Z

A

Z

Y

YT

TTY

Y

TY

n

n

nn

n

neutronneutron


Concettina Sfienti

Isotopic Effects Global N/Z effects are small Isotope distributions exhibit memory and

structure effects Temperature invariant with N/Z in

contradiction to limiting temperature assumption

Isoscaling Isoscaling data extended into the

vaporization regime Reduced symmetry term at freeze-out

…something….


What have we learnt?

Concettina SfientiConclusion & Outlook

…need to be answered…

•Why does the limiting temperature approximation seem to work so well for the masses but not for the isospin?

• Isoscaling...why does it work so well?

•Does really remain constant?

Unique Chance: NEUTRONS!


S.BianchinS.Bianchin, K.Kezzar, , K.Kezzar, A.Le FèvreA.Le Fèvre, J.Lühning , J.Lühning J.LukasikJ.Lukasik, U.Lynen, W.F.J. Müller, H.Orth, A.N.Otte, , U.Lynen, W.F.J. Müller, H.Orth, A.N.Otte,

H.Sann, H.Sann, C.SfientiC.Sfienti, C.Schwarz, A.Sokolov, , C.Schwarz, A.Sokolov, W.TrautmannW.Trautmann, J. Wiechula, M.Hellström, D.Henzlova, , J. Wiechula, M.Hellström, D.Henzlova,

K.Sümmerer, H.Weick, P.Adrich, T.Aumann, K.Sümmerer, H.Weick, P.Adrich, T.Aumann, H.Emling, Y.Leifels, R.Palit, H.Simon, H.Johansson, H.Emling, Y.Leifels, R.Palit, H.Simon, H.Johansson,

M.De NapoliM.De Napoli, G.Imme', G.Raciti, E.Rapisarda, , G.Imme', G.Raciti, E.Rapisarda, R.Bassini, C.Boiano,I.Iori, A.Pullia,R.Bassini, C.Boiano,I.Iori, A.Pullia, W.G.Lynch, W.G.Lynch,

M.Mocko, M.B.Tsang, M.Wallace, C.O.Bacri, M.Mocko, M.B.Tsang, M.Wallace, C.O.Bacri, A.Boudard, J-E.Ducret, A. Lafriakh, E.Le Gentil, A.Boudard, J-E.Ducret, A. Lafriakh, E.Le Gentil,

C.Volant, T. Barczyk, C.Volant, T. Barczyk, J.BrzychczykJ.Brzychczyk, J.Cibor, Z.Majka, , J.Cibor, Z.Majka, A.Mykulyak, A.Mykulyak, P.PawlowskiP.Pawlowski, A.Wieloch, B. Zwieglinski, , A.Wieloch, B. Zwieglinski,

B.Czech and B.Czech and A.S.BotvinaA.S.Botvina


...seems to...

Concettina Sfienti

PreAmpPreAmp

Anode wiresAnode wires

Resistive chargeResistive chargedivision readoutdivision readout

Pad readoutPad readoutin groupsin groups

12 mm pad modulo-five connected

Reduces the number of readout ch. from 80 to 17

Fine position determination from PAD readout Rough

position from charge-division method of the anode wires

Resolve the position ambiguity.

Anode & Pad Readout

The ALADiN Recipe

Concettina Sfienti, GSI Darmstadt

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