Overview of Nuclear Science

W. Nazarewicz

Nuclear science addresses the quantum quark/gluon and

nuclear many body problems. How do we understand nuclei in

terms of their fundamental parts and interactions?

The National Superconducting

Cyclotron Laboratory@Michigan State University

Bet ty Tsang

International Collaboration for High Energy Nuclear Physics

and China's Opportunity, June 28-29, Shanghai, China

The Rare Isotope Accelerator (RIA) and its Physics

World Wide Facilities in RIB

NSCL Coupled Cyclotron Upgrade

Notre Dame TwinSol

Sao Paulo

GANILLISE/SISSY

SPIRAL

Dubna

GSI FRS/ESR

Louvain-la-Neuve

ARENAS 3

TRIUMF ISAC

LBL Bears

Texas A&M

ORNLHRIBF

JAERI/KEK

Legnaro SPESDelhi NSC Calcutta VECC

ANL

RIA

CataniaEXCYPT

CERN ISOLDEREX-ISOLDE

SIRIUSRIKEN

Radioactive Beam Factory

MunichMAFF

Beijing AtomicEnergy Institute

Lanzhou

Red indicates in-flight separated RNBs.

RIA is the next-generation radioactive ion beam facility for basic research in nuclear physics planned for the United States.

Deliver radioactive beams of greater intensity and variety.

Comparison of RIA to other RI Facilities

• NSCL CCF (MSU) is lower in yield by a factor of 20 for the lightest elements and more than 1,000,000 for heavier elements and no post acceleration.

• ISAC/TRIUMF (Canada) is limited to traditional ISOL production of ions; i.e., limited set of beams.

• RIKEN RIF (Japan) will have 400 MeV/nucleon uranium, but has 20x less efficient acceleration and no post acceleration capability.

• GSI/FAIR (Germany) will have 1.5 GeV/nucleon uranium but with 10x less intensity (larger for other beams) and no post acceleration capability.

Cra

b P

uls

ar

The Science of Rare Isotopes

The Origin of the Elements

and the Nature of Compact

Stellar Objects

•What is the origin of the elements?

•How do stars live and how do they die?

•What happens during the explosion of a star?

•What processes occur on the surface of

white dwarfs and neutron stars?

Hub

ble

ST

Crab PulsarSupernova 1987a

The Limits of Nuclear Stability &

Properties of Exotic Nuclei•What combinations of

neutrons and protons does

nature allow to form a

nucleus?

•Which combinations of

protons and neutrons can

make up a nucleus?

•How must existing

theoretical models be changed

to describe the properties of

rare isotopes?

•What are the properties

of nuclei with extreme

neutron-to-proton ratios?

Equation of State (EOS) of Asymmetric

Nuclear Matter

The EOS is important for supernova explosions

Experimental constraints on the EOS of symmetric nuclear matter

Danielewicz, Lacey, Lynch, Science 298,1592 (2002)

•Range of EOS options is already constrained, but little is known about symmetry energy term

• Mean field depends on density and momentum

• Nucleus-nucleus collisions are also sensitive to in-medium NN cross-sections

HI collisions

Size & Structure of Neutron Star depends on EOS

D. Page

Dense neutron matter.

Strong mag. field.

Strange composition

pasta and anti-pasta

phases; kaon/pion

condensed core …

EOS influence

R,M relationship

maximum mass.

cooling rate.

core structure

The only laboratory option of reaching such densities is via nucleus-nucleus collision experiments --RIA will allow unprecedented variation of N/Z for such collisions

•2000—NSCL/MSU publishes “Opportunity with fast beams”

“Political” Steps Towards RIA•1989—The concept of a major facility for radioactive ion beams is introduced at the Nuclear Science Advisory Committee (NSAC) Long Range Plan (LRP) town meetings.

•1990—The IsoSpin Laboratory (ISL) steering committee forms to promote the development of rare isotope science.

•1996—The 1996 NSAC LRP endorses the Rare Isotope Accelerator (RIA) as the next new construction project.

•1997—Columbus Workshop discusses science with ISOL beams.

•1995-98—ORNL and ANL develop schemes for an ISOL-based rare isotope accelerator.

•1998—NSAC appoints the ISOL Task Force to evaluate the technical merits of ANL and ORNL proposals.

•2001—The NSAC LRP endorses RIA as the highest priority for major new construction.

•2004—RIA tied for 3rd place for future scientific facilities supported by the Department of Energy (DOE) to be built in 20 years.

Classical ISOL (isotope separation on line) Facility Concept

Excellent beam quality and low beam energies are possible

Limited to longer lifetimes ( > 1s)

Isotope extraction and ionization efficiency depend on chemical properties of element: difficult, element-specific development paths

The most neutron-rich isotopes will have too low intensities and too short lifetimes to be suitable for re-acceleration

Production of Rare Isotopes at Rest

1. Random removal of protons and neutrons from heavy

target nuclei by energetic light projectiles (pre-

equilibrium and equilibrium emissions).

2. Extraction of rare isotopes by diffusion; ionization

and acceleration: beams of high quality.

Target Spallation

Production of Rare Isotopes in Flight

hot participant zone

projectile fragment

1. Random removal of protons and neutrons from heavy

projectile in peripheral collisions.

projectile

target

2. De-excite by evaporation.

projectile fragment

“radioactive beam”

Projectile Fragmentation

RIA ConceptCombines advantages of projectile & target

fragmentation techniques

The Rare Isotope Accelerator (RIA) Concept

Why Choose a Beam Energy of

400 MeV/nucleon

Dramatic increases

in yield until 400-

500 MeV/nucleon

independent of the

production methods

Physics Programs at RIA

Stopped beams

• Masses

• bdecays, traps

<1 MeV beams

Astrophysics • p-, a-induced reaction rates

(direct measurements)

• resonant scattering

<10 MeV beams• Evolution of nuclear structure

•New magic numbers

•Paring (w-nucleon transfer)

•Dynamical symmetries, Coulex,

•Inelastic HI scattering

>100 MeV beams

• nuclear structure – extreme limits

• direct reactions

• Mass measurements

• charge exchange reactions

• Coulex of relativistic HI

• Nuclear Equation of State

Neutron Facility• reaction rates

•Isotope harvesting

Standard Models

• precision masses

• New techniques,

• Foundamental symmetries

ANL

NSCL

Proposed layout of RIA at ANL

MSU Proposed RIA Layout

Lansing

Detroit

Ann Arbor

Aerial View of MSU Campus at East Lansing

North

Aerial View of Potential RIA Sites at MSUN

ort

h

Key Steps Towards the Rare

Isotope Accelerator•1989—The concept of a major facility for radioactive ion beams is introduced at the Nuclear Science Advisory Committee (NSAC) Long Range Plan (LRP) town meetings.

•1990—The IsoSpin Laboratory (ISL) steering committee forms to promote the development of rare isotope science.

•1996—The 1996 NSAC LRP endorses the Rare Isotope Accelerator (RIA) as the next new construction project.

•1997—Columbus Workshop discusses science with ISOL beams.

•1995-98—ORNL and ANL develop schemes for an ISOL-based rare isotope accelerator.

•1998—NSAC appoints the ISOL Task Force to evaluate the technical merits of ANL and ORNL proposals. •2000—NSCL/MSU publishes “Scientific Opportunities for Fast Fragmentation Beams from RIA”

•2001—The NSAC LRP endorses RIA as the highest priority for major new construction.

•2004—RIA tied for 3rd place for future scientific facilities supported by the Department of Energy (DOE) to be built in 20 years.

•2005—President Bush proposed 3.8% cuts in DOE science.

•2005—Congress recommended DOE nuclear science increased by 3.9%

??

100

150

200

250

10

-310

-210

-110

010

1

2830 32 34 36 38 40 42 44 46 48 50 52 54 56 58

6062

6466 68

7072

74 7678

8082

8486

88 90

92 9496

98100 102

104106

108110

112 114

116 118120

122124

126

128130 132

134 136138

140 142 144 146 148150

152154

156

158

160

162

164 166 168 170 172 174176

178180 182

184

186188 190

26

28

30

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60

62

64

66

68

70

72

74

76

78

80

82

84

86

88

90

92

94

96

98

100

N=82

N=126

NSCL/MSU

RIA

— Masses

— Decay properties

— Level structure

— n-capture rates (indirectly)

Heavier Elements - Neutron Rich Nuclei

The NSCL will do

RIA physics using

fragmentation and

trapped beams up to

mass A ~ 80

NSCL FactsA national user facility for rare isotope research and education in nuclear science, nuclear astrophysics, accelerator physics.600 users from 23 countries

Biochemistry

NSCL

Chemistry

Biomedical & Physical Sciences

Plant BiologyLaboratories

Plant Science Greenhouses

~270 employees, incl. 60 undergraduate and 50 graduate students, 25 faculty

National Superconducting Cyclotron Laboratory

K500

World’s first superconducting cyclotron (1982)

K1200World’s most powerful

superconducting cyclotron (1989)

A1900

Coupled Cyclotron Facility (2000)

Experimental Areas at NSCL

Key Steps Towards the Rare

Isotope Accelerator

Current Status

R&D continue; Research with

existing RI facilities such as NSCL

Stop Iraq war for one week RIA

Key Steps Towards the Rare

Isotope Accelerator

•1989—The concept of a major facility for radioactive ion beams is introduced at the Nuclear Science Advisory Committee (NSAC) Long Range Plan (LRP) town meetings.

•1990—The IsoSpin Laboratory (ISL) steering committee forms to promote the development of rare isotope science.

•1996—The 1996 NSAC LRP endorses the Rare Isotope Accelerator (RIA) as the next new construction project.

•1997—Columbus Workshop discusses science with ISOL beams.

•1995-98—ORNL and ANL develop schemes for an ISOL-based rare isotope accelerator.

•1998—NSAC appoints the ISOL Task Force to evaluate the technical merits of ANL and ORNL proposals.

•2001—The NSAC LRP endorses RIA as the highest priority for major new construction.

•2004—RIA tied for 3rd place for future scientific facilities supported by the Department of Energy (DOE) to be built in 20 years.

•2005—President Bush proposed 3.8% cuts in DOE science.

•2005—Congress recommended DOE nuclear science increased by 3.9%

The Science of Rare Isotopes

•The origin of the elements in the cosmos.

•The limits of nuclear existence.

•The properties of nuclei with extreme ratios of neutrons to protons.

•The equation of state of neutron-rich nuclear matter.

•Physics beyond the standard model of particle physics.

•Applications in radiation safety, medical physics etc.

Scientific Reach of CCF

331

330

329

328

10 15 20Time (s)

0.01

0.1

1

10

40 50 60 70 80 90

solar abundancehalo abundance

Rela

tive A

bu

nd

an

ce

Element Number

U-T

h c

hro

no

mete

r?

nearly identical abundances

differentabundances

CS22892-052(HST)

Metal poor halo star

(Keck, HST)

Supernova

(HST)

10 20 30Wavelength (A)

V382 VelNe

Nova (Chandra)

N

Z

>10-5/s

>10-2/s>10/s>104/s

>107/s

X-ray burst (RXTE)

331

330

329

328

32710 15 20

Time (s)

4U1728-34

Experimental Areas at NSCL

Comparison of Rare Isotope

Intensities

Are there other ways or other facilities

that could answer these questions?

• The enormous opportunities offered by advanced rare isotope accelerator facilities are recognized worldwide, and significant inroads will be made by existing projectile fragmentation and ISOL facilities — and the new ones planned or under construction.

• RIA will be needed to do the job right.

• RIA will be the most powerful and versatile facility in the world and exceed the capabilities of

— ISAC by 1-2 orders of magnitude and more for non-ISOL beams (only low-energy beams)

—NSCL by up to two orders of magnitude for lighter nuclei and up to four or five orders of magnitude for heavy nuclei (no reaccelerated beams)

—RIKEN by two orders of magnitude (no reaccelerated beams)

—GSI (newly approved upgrade) by more than one order of magnitude (no reaccelerated beams)

Schematic of a Projectile Fragmentation Facility

High-energy beams (E/A > 50 MeV) of modest beam quality

Physical method of separation, no chemistry

Suitable for short-lived isotopes ( > 10-6 s)

Low-energy beams are difficult

Solution – stop in gas cell & reaccelerate

What is unique about the RIA linac?

• Possibility to optimize the production method

• Multiple charge state acceleration

– 400kW beam power

– highest efficiency for rare stable isotope acceleration, e.g., 48Ca, 124Sn (this can yield gains of 100 to 1000)

• 10x more intense uranium beams than any other planned facility

• Liquid Li production target + fragment separator + gas catcher system

– Ability to handle 400 kW beams

– Precision reaccelerated beams without chemical or half-life dependence

– Same setup for all elements with short development times

• 2.1 GeV 3He at 8x intensity for ISOL targets

Low-energy Experimental Area Important to make design compatible with very different types of targets

Mass separators with beam cooling may be better & cheaper – R&D Required

Post accelerator ( 10 MeV/u for A up to 240, 20 MeV/u for A<60)

High Energy Experimental Area

The Advantages of RIA at MSU

•Michigan State University is one of the top research

universities in the world.

•Locating RIA at MSU guarantees that the vitality and

visionary leadership that has characterized the NSCL to date

will advance rare isotope research in the United States in its

next stage of development.

•Locating RIA at MSU also guarantees that nuclear science

research will be within reach of some of the top students in

the nation.

•RIA at MSU will be poised at the intersection of past and

future, providing a vital link to tomorrow’s world.MAIN

Aerial View of MSU Campus at East Lansing

NSCL

Complementary Production Techniques

Nuclear Astrophysics at RIA

Stopped beams

• Masses

• b,bn,bp,p decays

<1 MeV beams

• p-, a-induced reaction rates

(direct measurements)

• resonant scattering

<10 MeV beams• p-,a-,n-induced reaction rates

(ANC,nucleon transfer, …)

• nuclear structure experiments

>100 MeV beams

• p-,a-,n-induced reaction rates

(transfer/knockout, Coulomb breakup)

• b,bn,bp,p decays

• charge exchange reactions

• TOF mass measurements

• Nuclear structure experiments

Neutron Facility• n-capture on

radioactive targets

Schatz

The Discovery Potential of RIA

C-L. Jiang et al. ANL/NSCL