Challenges for EURISOL and the EURISOL Design Study

Yorick Blumenfeld

OUTLINE

• The « Standard » scientific case • The EURISOL concept and performances • Technical Challenges and the Design Study • Task 10 : Physics and Instrumentation • Goals of the Workshop

The Nuclear Chart and Challenges

ab initio

calculations for light nuclei

• Systematic study of light nuclei (A<12) shows the necessity of including a 3-body force R.B. Wiringa and S.C. Pieper, Phys. Rev. Lett.

89

(2002) 182501

Modification of magic numbers far from stability

E* (MeV) 4 3 Lowest 2 + 2 1 0

12 Mg 20 Ca 16 S

12 16 20 24

N

state

Effect of shell closures on element abundances

46

Ar(d,p) 10 MeV/A @ SPIRAL with MUST

L. Gaudefroy, thèse

Neutron-proton pairing

• n-p pairing can occur in 2 different states: T=0 and T=1. The former is unique to n-p. It can be best studied in N=Z nuclei through spectroscopy and 2-nucleon transfer reactions.

Collective Modes

• Atomic nuclei display a variety of collective modes in which an assembly of neutrons moves coherently [e.g Low-lying vibrations and rotations.

•

Challenge

:Will new types of collective mode be observed in neutron-rich nuclei in particular? • Will the nucleus become a three fluid system-made up of a proton and neutron core plus a skin of neutrons?

We will then get collective modes in which the skin moves relative to the core.

From W. Gelletly

Two-proton radioactivity near the proton drip-line

Proton energy and angle correlations



di-proton emission?

Two-proton decay

~80%

Q 2p MeV = 1.14

~20%

T 1/2 = 3.8 ms J. Giovinazzo et al., PRL89 (2002) 102501

Super heavy elements : discovery and spectroscopy

GSI Z



112 RIKEN Z=113 DUBNA Z to 118?

294 118

  

Synthesis of new elements/isotopes (Z



120) Spectroscopy of Transfermium elements (Z



Shell structure of superheavy nuclei 108)

Studying the liquid-gas phase transition far from stability

Muller Serot PRC 1995 Neutron rich nuclei: isospin distillation Bonche Vautherin NPA 1984

asymmetry

r

p /

r

n

Proton rich nuclei: vanishing limiting temperatures From Ph. Chomaz and F. Gulminelli

Radioactive beam production: Two complementary methods GANIL/SISSI, GSI, RIKEN, NSCL/MSU High energy, large variety of species , Poor optical qualities, lack of energy flexibility GANIL/SPIRAL, REX/ISOLDE, ISAAC/TRIUMF good beam qualities, flexibility, intensity Low energy, chemistry is difficult

The NuPECC Recommendation NuPECC recommends the construction of 2 ‘next generation’ RIB infrastructures in Europe, i.e. one ISOL and one in-flight facility. The in-flight machine would arise from a major upgrade of the current GSI facility, while EURISOL would constitute the new ISOL facility

The EURISOL Road Map

• Vigorous scientific exploitation of current ISOL facilities : EXCYT, Louvain, REX/ISOLDE, SPIRAL • Construction of intermediate generation facilities : MAFF, REX upgrade, SPES, SPIRAL2 • Design and prototyping of the most specific and challenging parts of EURISOL in the framework of EURISOL_DS.

SPIRAL2

The EURISOL Concept

The EURISOL Concept

Total cost : 613 M€

Some beam intensities

Calculations for EURISOL : Helge Ravn 6 He 5X10 13 pps 18 Ne 5X10 12 pps

Yields after acceleration Comparison between facilities

a) Kr isotopes a) Yield for in-flight production of fission fragments at relativistic energy

Experimental Areas Low Energy Astrophysics Structure Reactions

The Major Technological Challenges for EURISOL

• 5 MW proton accelerator also capable of accelerating A/Q = 2.

• Target(s) sustaining this power and allowing fast release of nuclei • Efficient and selective ion sources producing multi-charged ions • Multi charge state acceleration of radioactive beams with minimal losses • Radioprotection and safety issues

The EURISOL_DS in the 6

th

framework

• Detailed engineering oriented studies and technical prototyping work • 21 participants from 14 countries • 21 contributors from Europe, Asia and North America • Total Cost : 33 M€ • Contribution from EU : 9.16 M€

11 Tasks

• • • •

Physics, beams and safety

– Physics and instrumentation (Liverpool) – Beam intensity calculations (GSI) – Safety and radioprotection (Saclay)

Accelerators :

Synergies with HIPPI (CARE)

– Proton accelerator design (INFN Legnaro) – Heavy ion accelerator design (GANIL) – SC cavity development (IPN Orsay): SC cavity prototypes and multipurpose cryomodule

Targets and ion sources :

Synergies with spallation sources

– Multi-MW target station (CERN) : mercury converter – Direct target (CERN) : Several target-ion source prototypes – Fission target (INFN Legnaro) : UC x target

BB :

Synergies with BENE

– Beam preparation (Jyväskylä) : 60 GHz ECR source – Beta-beam aspects (CERN)

TASK 10 : Physics & Instrumentation

• Robert Page, Angela Bonaccorso, Nigel Orr • Expected Deliverables – Broad scientific goals selected – Key experiments selected – Evaluation of feasibility – Conceptual design of apparatus – Costing of instrumentation – Definition of beam properties

Goals of the Workshop

• Update the Physics Case : new ideas and new concepts.

• What are the key experiments concepts?

which will test these • What are the requirements of the facility : species, energy, ….

• How do we carry forward the involvement of theoreticians in the Design Study, and more generally in the EURISOL road map.

Combination of beta beam with low energy super beam Unique to CERN- based scenario combines CP and T violation tests



e

  m

(



+) (T)

 m  

e (

p

+ ) (CP)



e

  m

(



-) (T)

 m  

e (

p

)

CERN-SPL-based Neutrino SUPERBEAM 300 MeV

 m

Neutrinos small contamination from



e (no K at 2 GeV!) Fréjus underground lab.

A large underground water Cerenkov (400 kton) UNO/HyperK or/and a large L.Arg detector. also : proton decay search, supernovae events solar and atmospheric neutrinos. Performance similar to J-PARC II There is a window of opportunity for digging the cavern starting in 2008 (safety tunnel in Frejus or TGV test gallery)

CERN :



-beam baseline scenario

FAIR

Time scales

2005 2007 2010 2012 2016 Project definition Construction Exploitation

AGATA

(A dvanced

GA

mma

T

racking

A

rray)

4

π γ

-array for Nuclear Physics Experiments at European accelerators providing radioactive and high-intensity stable beams Main features of AGATA

Efficiency: 40% (M γ =1) 25% (M γ today’s arrays ~10% (gain ~4) =30) 5% (gain ~1000) Peak/Total: 55% (M γ =1) 45% (M γ =30) today ~55% 40% Angular Resolution: ~1º  FWHM (1 MeV, v/c=50%) ~ 6 keV !!!

today ~40 keV Rates: 3 MHz (M γ =1) 300 kHz (M γ today 1 MHz 20 kHz =30)

• 180 or 120 large volume 36-fold segmented Ge crystals in 60 or 40 triple-clusters • Digital electronics and sophisticated Pulse Shape Analysis algorithms allow • Operation of Ge detectors in position sensitive mode

 γ

-ray tracking • Demonstrator ready by 2007 • Construction of full array from 2008 ??

J. Simpson

The Rare Isotope Accelerator (USA)

RIA

(USA)