Activity at LNL and SPES
Download
1 / 57

Activity at LNL and SPES - PowerPoint PPT Presentation


  • 100 Views
  • Uploaded on

Activity at LNL and SPES. L.Corradi Laboratori Nazionali di Legnaro – INFN, Italy. AN2000 2 MV. CN 7 MV. PIAVE HI Injector. The LNL accelerators. ALPI Linac 40 MVeq. Tandem XTU 15 MV. Transnational access. Open Calls for LoIs for the INFN research infrastructures May 2007.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Activity at LNL and SPES ' - elin


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Activity at LNL and SPES

L.Corradi

Laboratori Nazionali di Legnaro – INFN, Italy

Nupecc Meeting Catania, March 12, 2010


AN2000 2 MV

CN 7 MV

PIAVE HI Injector

The LNL

accelerators

ALPI Linac 40 MVeq

Tandem XTU 15 MV


Transnational access

Open Calls for LoIsfor the

INFN research infrastructures

May 2007

50 LoIs

312 potential users

from 15 countries

(about 30% more than presented at the VI FP)

E.Fioretto


Nuclear structure research

GASP

CLARA

AGATA demonstrator

- High spin states

- Collectivity and shell model

- Isospin symmetries

- Isospin mixing in N=Z nuclei

- Spectroscopy at the dripline

- Shell stability and evolution

in neutron rich nuclei

- Symmetries at the critical point

- Rotational damping


Reaction dynamics research

PRISMA and PISOLO

EXOTIC

GARFIELD and 8πLP

  • Multinucleon transfer

  • - Nuclear superfluidity (pair transfer)

  • - Elastic and inelastic scattering

  • - Near and sub-barrier fusion

- Multifragmentation at low excitation energies

- Nuclear level density

- Collective modes of excitations

- Break up processes

- Quasi elastic scattering with light ions produced in secondary reactions


target

MOT

Fundamental interaction studies

the TRAPRAD experiment : production and trapping of Fr isotopes

LNL-FE-SI collaboration

18O+197Au

Francium is the heaviest alkali, has a simple electronic structure and has enhanced P and T violation effects

18O beam I= 200 pnA

I ~ 5x105 ions/sec

trapped 8000 210Fr isotopes


% distribution of beam on target among the different set-up’s

LNL PAC Feb2006

average rejection factor for nuclear physics experiments over the last five years : 45-65%

LNL PAC Feb2010


Conventional array set-up’s

Segmented detectors

g-ray tracking

Energy (keV)

The innovative use of detectors (pulse shape analysis, g-ray tracking, digital DAQ) will result in high efficiency (~40%) and excellent energy resolution

Objective of the final R&D

phase 2003-2008

5 asymmetric triple-clusters

36-fold segmented crystals

540 segments

555 digital-channels

Eff. 3 – 7 % @ Mg = 1

Eff. 2 – 4 % @ Mg = 30

Full ACQwith on line PSA and g-ray tracking

The AGATA

DEMONSTRATOR

Major issue (in the demonstration phase) is the Doppler correction capability

 coupling to beam and recoil tracking devices

PRISMA

D.Bazzacco


Present set up: set-up’s

3 triple clusters

4th triple being installed now

Original and Doppler-corrected spectra for the 847 keV 56Fe 2+  0+ lineDirection of recoils determined by the MCP Dante

547 keV

(197Au)

847 keV

( 56Fe)

56Fe  197Au

220 MeV

Dante+PSA

2.6 keV

Dante+PSA

4.6 keV

Original

~10 keV

Original

~30 keV


neutrons set-up’s

protons

Physics program : evolution of magic numbers and collectivity in neutron rich nuclei, but not only…

Proton drip-line

More than 20 LoI:

Highly Excited Collective Modes.Proton-rich mirror nuclei.Superdeformed states in A~40 proton-rich region.Order-Chaos transition in warm rotating nuclei.etc...

Neutron drip-line

Evolution of collectivity and Dynamical Symmetries in the rare earths

n-rich nuclei

Mix-symmetry states

Quenching of the N=82 shell gap in n-rich nuclei

N=50 shell gap: lifetime, and excited states

Lifetimes in neutron-rich Ca isotopes

Spectroscopy and lifetimes in the new region of deformationn-rich A~60, N~40 nuclei

Lifetimes in the region of the island of inversion


THE PRISMA SPECTROMETER + CLARA GAMMA ARRAY set-up’s

INFN exp. PRISMA (LNL,PD,TO,Na)

INFN exp. GAMMA (LNL,PD,Fi,MI,Na,Pg)

+ broad Int. Collaboration (UK,F,D,Pl,Sp,Ro,Hr)

PRISMA: a large acceptance

magnetic spectrometer

W  80 msr; Brmax = 1.2 Tm

DA/A ~ 1/200

Energy acceptance ~±20%


Multineutron and multiproton transfer channels near closed-shell nuclei

90Zr+208Pb Elab=560 MeV

pure neutron pick-up channels

Mass [amu]

PRISMA spectrometer data

GRAZING code calculations

L.Corradi et al, J.Phys G36(2009)113101 (Topical Review)


Near- and sub-barrier fusion reactions closed-shell nuclei

Precise measurements of fusion excitation functions allow to

probe nuclear structure effects:multi-dimentional tunnelling, influence of surface vibrations and transfer channels on reaction dynamics

understand synthesis of superheavy elements

measure rates of reactions of astrophysical interest

cross section measurements at far sub-barrier energies may probe the nuclear potential inside the Coulomb barrier

A.M.Stefanini et al PRC78(2008)044607

A.M.Stefanini et al., PRC76(2007)014610


136 closed-shell nucleiXe

96Zr

82Se

70Zn

64Ni

48Ca

36S

26Mg

40Ar

22Ne

THE PRISMA + CLARA CAMPAIGN

Grazing reactions as a tool to study n-rich nuclei

To do that we used the most neutron-rich stable beams available at the Tandem/PIAVE-ALPI accelerator complex of LNL at energies 5-15% above the Coulomb barrier

14


New points closed-shell nuclei

58Cr

Gamma softness in heavy Cr and Fe isotopes

populated in 64Ni+238U at Elab=404 MeV

Cr (-4p)

N.Marginean et al., Phys. Lett. B 633(2006)696

dynamical symmetries

  • The R(E4/E2) ratio for the heavy Fe isotopes is very close to the 2.50 value characteristic of g-soft rotors

  • The value for the heavier Cr isotopes is also close to the same limit

  • 58Cr lies exactly at the 2.20 value predicted for the E(5) dynamical symmetry. The energies of the yrast band are in good agreement with the predictions of this symmetry. Transition probabilities are essential to decide whether 58Cr lies or not at the E(5) critical point.


Lifetimes measurements in closed-shell nuclei48Ca+208Pb at Elab=310 MeV

Differential Plunger Method

comparison of deduced B(E2) with large scale shell model calculations

J.J.Valiente-Dobon et al, PRL102(2009)242502


AGATA Demonstrator/1 closed-shell nucleiΠ

Experimental program

July 2013 GANIL/SPIRAL2 ~15TC

June 2011  LNL6TC

Dec 2011  GSI/FRS≥ 8TC

AGATA D.+PRISMA

AGATA @ FRS

AGATA + VAMOS + EXOGAM

Total Eff. ~6%

Total Eff. > 10%

Total Eff. > 20%


  • GARFIELD+HECTOR Campaign closed-shell nuclei

  • Temperature dependence of GDR

  • Isospin Mixing of N=Z nucleus 80Zr at high T

  • Dynamic Dipole in N/Z asymmetric reaction

  • Search for the Jacobi shape transition in light nuclei

  • Onset of the multi-fragmentation and the GDR

Nuclear structure at finite temperature

Coincident measurements : g +LCP + residues @ 5-20MeV/A

PPAC or Phoswich

Residues selection

GARFIELD: 180 E-DE telescopes

Light Charged Particles

HECTOR: 8 Large BaF2

High-energy g-rays

F.Gramegna, A.Bracco et al,

LNL-MI collaboration


GARFIELD+HECTOR set-up – GDR studies in hot and thermalized

nuclei : damping of collective modes at finite temperature

Two reactions – same compound

16O (130,250 MeV ) + 116Sn 132Ce*

64Ni (300,400,500 MeV) + 68Zn 132Ce*

Agreement with thermal fluctuation model if and only if CN evaporation width is included

Analysis of α particle spectra shows preequilibrium effects in 16O+116Sn

Increase of GDR width is due to deformation effects

GDR analysis with no preequilibrium effects in 64Ni+116Sn

O. Wieland et al., PRL97(2006)012501


GARFIELD : studies of response of silicon detectors - channelling

effects and digital pulse shape

DIGITAL PULSE SHAPE on 500μm Silicon

The FAZIA Initiative

32S +27Al @ 474 MeV

Final goal: build the full array for lower (SPIRAL2 / LNL / SPES) and higher energy (GANIL / LNS / FAIR / EURISOL / RIA) studies with exotic and stable beams.

Ne

F

O

N

C

B

Be

Randomimpingingions

channelling spoils mass identification

300 μ

500 μ

G.Poggi


SPES ISOL facility channelling

  • Cyclotron 750 μA,70 MeV (max) for protons in twoexit ports:

  • RIB - up to 300 μA p on UCx

  • Application - up to 500 μA

Additional target station (special plants second priority)

RIB or neutron production

transport/beam cooler/separator

High Resolution Mass Spectrometer 1/20000

Charge Breeder

1+  n+

UCx target station 1013 fission/s

(PostAccelerator)

G.Prete


ALPI layout channelling

ALPI upgrade for SPES

Optimum beta

βo = 0.047

βo = 0.056

βo = 0.11

βo= 0.13

To be funded:

2 additional LowBeta Cryostats (CR1, CR2) a New buncher

New magnetic lenses (upgrade from 20 to 30 T/m)

Funded upgrade (2009)

LowBeta CR3, new couplers

22


The ALPI post accelerator channelling

Expected SPES energies

  • Superconductinglinac based on QW Resonators

  • 2003: Up graded to Veq ~ 40 MV - Nb/Cu sputtered cavities or bulk Nb cavities; 2009: 48 MV

  • Energies up to 10-12 MeV/A for A=130 beams


Representative expected beams at SPES channelling

ionization efficiencies:

(1+) 30% and (n+) 4%

(1+) 90% and (n+) 12% for Kr and Xe,

Transport efficiency 50%


SPES SCHEDULE channelling



Radioactive Beams channelling

Dynamical Dipole Yields

Dynamical Dipole yield increases with asymmetry of fusing ions

LOI SPIRAL2

Dynamic Dipole in172Yb

 5MeV/A

(onset energy for DDR)

Information can be extracted on the symmetry energy term at low density

S.Leoni

Baran, Brink, Colonna, DiToro PRL87(2001)182501


proton pick-up channels lead to neutron rich heavy mass nuclei

proton stripping channels lead to neutron rich medium mass nuclei


Multinucleon transfer reactions with neutron-rich beams nuclei

possibility to populate nuclei via pick-up and stripping of both neutrons and protons

probing (nn), (pp) and (np) correlations. Important for studies on pairing vibrations/rotations, nuclear superfluidity

production of neutron rich isotopes

GRAZING code calculations

C.H.Dasso, G.Pollarolo, A.Winther, PRL73(1994)1907


Near- and sub-barrier fusion reactions with exotic beams nuclei

With the lower beam intensities of RIB, one can derive fusion barrier distributions by measuring excitation functions of quasi-elastic channels

Key issues with RIB

Enhanced effects of positive Q-value transfer channels

Role of surface modes in nuclei with significant neutron excess

F.Liang et al., PRC75(2007)054607

S.Mitsuoka et al, PRL99(2007)182701


Some few remarks nuclei

Nuclear structure and nuclear reactions with heavy ions are being investigated at near barrier energies with the TANDEM+ALPI+PIAVE accelerator complex of LNL

Important developments have been made in complex detector systems (gamma arrays, tracking spectrometers, charge particle arrays) through which extensive studies have been and are being successfully performed in different areas

The SPES project represents the most important step forward for nuclear physics research in Italy. Its completion will allow to perform challenging and significant studies in heavy ion physics with RIB’s


The SPES project nuclei

  • Facility Approved for construction

  • Phase 1 - financed by INFN

TANDEM XTU

Experimental HALLS

RIB Transport Line

III Experimental HALL

SPES

LINAC ALPI

Primary Beam: Cyclotron 300 μA,70 MeV (max) for protons in two exit ports for RIB

Production Target: UCx multi-foil , up to 1013 fission s-1

Post-accelerator: PIAVE-ALPISuperconductive Linac up to 11 AMeV for A=130


1 nuclei

2

H

He

3

4

5

6

7

8

9

10

Li

Be

B

C

N

O

F

Ne

14

15

11

12

13

16

17

18

Na

Mg

Al

Si

P

S

Cl

Ar

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

K

Ca

Sc

Ti

V

Cr

Mn

Fe

Co

Ni

Cu

Zn

Ga

Ge

As

Se

Br

Kr

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

Rb

Sr

Y

Zr

Nb

Mo

Tc

Ru

Rh

Pd

Ag

Cd

In

Sn

Sb

Te

I

Xe

55

56

57

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

Cs

Ba

La

Hf

Ta

W

Re

Os

Ir

Pt

Au

Hg

Tl

Pb

Bi

Po

At

Rn

87

88

89

104

105

106

107

108

109

110

111

112

Fr

Ra

Ac

Rf

Db

Sg

Bh

Hs

Mt

Ionization methods at SPES

Elements with bad volatility (NOT EXTRACTED)

Surface Ionization Method

Surface Ion source

Photo Ionization Method

Laser beam

Plasma Ionization Method

Laser Ion source

Main fission 238U fragments

Plasma Ion source


UCx emissivity nuclei

The SPES target prototype

UCx target procuction

Graphite Window

UCx Disk

Graphite Dumpers

SPES target-ion-source Front End

SEM Characterization

Graphite Box


SPES Target collaborations network nuclei

TRIUMF- ISAC

KEK- TRIAC

ORNL- HRIBF

SPES

UNIPV

UNIPD

UNITN

DCT- Structure and

Transportation Engineering

DIM- Mechanical Eng.

DEI-IT – Eng.

Chemistry

DIM

DIM

DCT

DEI

Chemistry

CONTROLS

HANDLING

DESIGN

MATERIALS

CERN- ISOLDE

LNL

GANIL-SPIRAL 2

Pavia

Napoli

Milano

Catania

ORSAY-ALTO

Bologna

Firenze

LNS

Padova

UNIPA

Nucl. Engin.


PIAVE cryostat nuclei

Present layout

ISACII-like cryostats

SPES layout

PIAVE upgrade for SPES

38


Multinucleon transfer reactions in the transactinide region nuclei

Eurisol Project (key experiments) http://www.ganil.fr/eurisol/

Multinucleon transfer reactions are a promising tool to get access to very neutron rich heavy nuclei when using a neutron rich radioactive beam

GRAZING calculations


Quasielastic barrier distributions : role of particle transfer channels

Exp. data : S.Mitsuoka et al, Phys.Rev.Lett.99,182701(2007)

Calculations : G.Pollarolo, Phys.Rev.Lett.100,252701(2008)


Charge transfer channels

NOT equilibrated

all degree of freedom EQUILIBRATED

Prompt

Dipole

Giant Dipole

Resonance

Temperature

dependence

of GDR width

damping of CN

Reaction

Dynamics

EOS

GDR

p vs n

Dipole Resonance Emission from HOT nuclei

density plot

fusion

CN

dipole moment

t=0 fm/c

CN

fusion


pre transfer channels

equilibrium

gspectra

GDR analysis with

NO pre-equilibrium effects

GARFIELD + HECTOR experiment @ LNL

Two reactions – same compound

16O (130,250 MeV ) + 116Sn 132Ce*

64Ni (300,400,500 MeV) + 68Zn 132Ce*

aparticle

spectra


Last stage of the decay revealed by correlation functions
Last stage of the decay revealed by correlation functions transfer channels

p+12C

d+

p+7Be

E*=0.7, 2.3 MeV

E*=2.3, 3.5 MeV

E*= 2.2, 4.3, 5.6 MeV

Primary yields can be obtained after Coulomb background subtraction


GARFIELD & Ancillaries transfer channels

Pre-equilibrium emission in 16O+116Sn

Measuring correlation functions

Experiments with n-rich/poor systems @ LNL32S+58Ni and 32S+64Ni 14.5 AMeV

R(q) probes space-time properties of source


Multinucleon transfer reactions : from neutron poor to neutron rich nuclei

LNL data

GRAZING code calculations 44Ar + 208Pb E=320 MeV

with (moderately n-rich) heavy ions one can populate (nn), (pp) and (np) channels with comparable strength


Approaching neutron rich nuclei 78Ni and 132Sn regions


Neutron rich nuclei produced in the fission of neutron rich nuclei 238U in

136Xe+238U at Elab=990 MeV

N.Marginean et al., Phys. Rev. C80(2009)021301(R)


Total cross sections neutron rich nuclei

successive transfer

S.Szilner et al, Phys.Rev.C76(2007)024604


MWPPAC neutron rich nuclei

IC

PRISMA spectrometer – trajectory reconstruction

  • A physical event is composed by the parameters:

  • position at the entrance x, y

  • position at the focal plane X, Y

  • time of flight TOF

  • energy DE, E


Population of neutron rich nuclei neutron rich nuclei

64Ni+238U at Elab=390 MeV

58Fe

most neutron-rich stable isotopes

54Cr

possibility to make spectroscopic studies of neutron rich nuclei moderately far from stability

50Ti

L.Corradi et al, Phys.Rev.C59(1999)261


multinucleon transfer : neutron rich nuclei

experiment vs. theory

data : LNL

theory : GRAZING code and CWKB

L.Corradi et al,

J.Phys.G36(2009)113101 (Topical Review)


Detection of (light) target like ions in inverse kinematics with PRISMA

beam direction

PRISMA

20o

40Ca

94,96Zr

Prisma acceptance

MNT channels have been measured down to 25 % below the Coulomb barrier

L.Corradi et al, LNL exp. March 2009


Detection of (light) target like ions in inverse kinematics with spectrographs

beam direction

Split Pole

> 10o

124Sn

58Ni

+1n

+2n

successive+direct pair transfer

+3n

RMS data

lacking of data for +2n in the deep sub-barrier region

H.Esbensen et al., PRC57(1998)2401

C.L.Jiang et al., PRC57(1998)2393



2 calculations+→0+

4+→2+

2+→0+

4+→2+

2+→0+

4+→2+

2+→0+

4+→2+

Softness in Cr and Fe isotopes populated in 64Ni+238U at Elab=404 MeV

Cr (-4p)

N.Marginean et al., Phys. Lett. B 633(2006)696

gating on mass

Fe (-2p)

S.Lunardi et al., Phys. Rev. C 76(2007)034303


A schematic view of fusion reactions calculations

E << Eb

E ~ Eb

E > Eb

σ

σ

σ

~ mb

µb - mb

nb - µb

E

E

E

V

V

V

r

r

r

- σsteep fall off

- CC effects

- fusion “hindrance”

- D(B) from fusion and QE processes

- structure of VN at r < rB

- σ fusion < σcapture

- connection with surface vibrations and transfer

- connection with QF, MNT, DIC, BU

- connection with astrophysics


Parity non conservation in atoms : a test of the Standard Model

Precision tests of the SM at low momentum transfer

complementary information obtained from atomic PNC and high energy electron-nucleon scattering experiments

constraints on relevant new physics below certain mass scales


Parity non conservation in atoms : a test of the standard model

with 133Cs reached precision below 1%

with radioactive beams

important to pursue experimental work on chain of isotopes

parity violation in specific atomic transitions

nuclear anapole moment

permanent electric dipole moment (time reversal symmetry violation)

Francium is the heaviest alkali, has a simple electronic structure and has enhanced P and T violation effects


ad