Nuclear Astrophysics at IMP Xiaodong Tang

Institute of Modern Physics Chinese Academy of Sciences

The r-Process Nucleosynthesis: Connecting FRIB with the Cosmos, May 31 - June 17, 2016

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OUTLINE • Jinping Underground lab for

Nuclear Astrophysics (JUNA) • Research with Heavy Ion

Research Facility at Lanzhou (HIRFL)

• Research with High Intensity Accelerator Facility (HIAF)

• Beijing ISOL @ CIAE

HIAF@ Huizhou

IMP@ Lanzhou

CIAE@Beijing

JUNA@ Xichang

Jinping Underground lab for Nuclear Astrophysics（JUNA）

Highly sensitive detector

Excellent background

First deep underground accelerator driven by ECR

Great People

CIAE,IMP,TSU,SJTU,SDU, SCU 2018: first experiment

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High Intensity heavy ion Accelerator Facility in Lanzhou (HIRFL) Currently ongoing activies

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111213

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1516

17181920

2122

2324

25262728

2930

3132

33343536

3738394041

424344

45464748

49505152

535455

56

5758

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H (1)He (2)Li (3)

Be (4) B (5) C (6) N (7)

O (8) F (9)

Ne (10)Na (11)

Mg (12)Al (13)Si (14) P (15)

S (16)Cl (17)

Ar (18) K (19)

Ca (20)Sc (21)

Ti (22) V (23)

Cr (24)Mn (25)

Fe (26)Co (27)

Ni (28)Cu (29)

Zn (30)Ga (31)

Ge (32)As (33)

Se (34)Br (35)Kr (36)Rb (37)

Sr (38) Y (39)

Zr (40)Nb (41)

Mo (42)Tc (43)

Ru (44)Rh (45)Pd (46)Ag (47)

Cd (48)In (49)

Sn (50)Sb (51)

Te (52) I (53)

Xe (54)

HCNO breakout

Mass

Weak rate

Mass, reaction rate and weak rate

Nuclear Processes on the surface of neutron star

rp-process

HCNO breakout

EC

neutrons

protons

Mass known Half-life known nothing known

Neutron star (Chandra) Weak rate

KS 1731-260

p process

Supernova (Chandra,HST,..)

E0102-72.3 AGB s-process 95Zr(n,γ)96Zr

abun

danc

e

solar r abundance observed

Z

CS22892-052

40 50 60 70 80 90-2

-1

0

1

Massive star 12C+12C

np-process 84Sr

Big Bang AGB 14C(,γ)18O

Origin of element

Neutron capture

Masses,reaction rates,weak rates

Modified based on Schatz’s slide

CSRe

CSRm 1000 AMeV (H.I.), 2.8 GeV (p)

RIBLL1 RIBs at tens of AMeV

RIBLL2 RIBs at hundreds of AMeV

Heavy Ion Research Facility at Lanzhou

Nuclear Astrophysics at HIRFL

CSRe

CSRm 1000 AMeV (H.I.), 2.8 GeV (p)

RIBLL1 RIBs at tens of AMeV

RIBLL2 RIBs at hundreds of AMeV

热CNO突破反应测量：次级束流线

高精度质量测量：冷却储存环

直接测量：低能核天体物理终端

Nuclear Astrophysics at HIRFL

电荷改变截面测量：外靶终端

Heavy Ion Research Facility at Lanzhou

Nuclear mass

Prediction >8000 Synthesized 3191 Precision<100 keV ~2000

1. B. Mei et al., NIM A 624, 109 (2010) 2. X. L. Tu et al., PRL 106, 112501 (2011) 3. X. L. Tu et al., NIM A 654, 213 (2011) 4. Y. H. Zhang et al., PRL 109, 102501 (2012) 5. X. L. Yan et al. Astrophys. J. Lett. 766, L8 (2013) 6. H. S. Xu et al., IJMS 349, 162 (2013) 7. X. L. Tu et al., J. Phys. G41, 025104 (2014) 8. W. Zhang et al., NIM A 756, 1 (2014) 9. B. Mei et al., Phys. Rev. C 89, 054612 (2014) 10. P. Shuai et al., Phys. Lett. B 735,327 (2014)

Beams: 56Ni, 78Kr, 86Kr, 112Sn

Precision 10-6~10-7

(20-200 keV)

Mass measurement at HIRFL

Improving Precision (27)

First Measurement (26)

64Ge was considered to be a waiting point

Sp(65As) >-250 keV (AME2003) The waiting points determine：

• Reaction flows • Burst duration • Final abundance

65As

Waiting point does not wait

Sp(65As) = -90 (85) keV

89%–90% of reaction flow passes 65As， 64Ge is not an important waiting point

New mass measurement finds that 64Ge is not a waiting point

time (s)

AME2003 (dashed) This work (solid)

~30 s

Waiting point does not wait

X.L. Tu et al., PRL106(11):112501

New experimental initiatives

RIBLL1 Ext. Target

Cooler Storage Ring

HCNO break out： Active Target

TPC

Reaction

HCNO breakout： Int. Target

Reaction

Weak rate： Charge

Exchange

Weakrate

rp、np： Double TOF

IMS

Mass

6 million USD awarded this morning!

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High Intensity Accelerator Facility (HIAF) A recently funded new Chinese project funded

How were the heavy elements from iron to uranium made?

铁

金 铀

• mass • stellar half life • Decay branching • Fission • n capture xsec

Superconducting Linac: Length: 180 m Energy: 17 MeV/u (U34+) CW and pulse modes

Booster Ring: Circumference: 471 m Rigidity: 34 Tm Beam accumulation Beam cooling Beam acceleration

Spectrometer Ring: Circumference:188.7 m Rigidity: 13T m Electron cooling Stochastic cooling In-ring experiment

High Intensity Accelerator Facility

Ions Energy Intensity

SECR 238U34+ 14 keV/u 0.05 pmA

iLinac 238U34+ 17 MeV/u 0.028 pmA

BRing 238U34+ 0.8 GeV/u ~1.41011 ppp

Main beam parameters

Unprecedented beam Intensity ( Comparison with HIRFL): - Primary beam intensity increases by 1000 – 10000 times

- Secondary beam intensity increases by ~10000 times

Precisely-tailored beams: - Beam cooling (electron, stochastic, laser; high quality, very small spot )

- Beam compression (Ultra-short bunch length: 150ns)

- Long period slow extraction (Super long, high energy, quasi-continuous beam)

Facility Competence

Production of RNB at higher energy

Neutron Number

Prot

on N

umbe

r Nuclides Available at HIAF

One of the world’s most powerful facilities to search for new isotopes

Boundary of Known Nuclei

Prolific sources of nuclides far away from the stability line will be provided using projectile fragmentation, in-flight fission, multi-nucleon transfer, and fusion reactions. The limits shown are the production rate of one nuclide per day, which enable the “discovery experiments”.

Particle/day

A=175

A=153

A/Z=2.6

A/Z=2.9

Charge state distribution complicates mass measurement

A Z Q IonName Mtoq[u/e] dm[keV] T[1/2][atomic] 155 58 58 ^{155}Ce^{58+} 2.670983 400# 200# ms 155 59 58 ^{155}Pr^{58+} 2.670843 17 1# s 163 61 61 ^{163}Pm^{61+} 2.670826 503# 200# ms

¾ 3 similar A/Q，Only 155Pr mass is known by now Contribution by X.L. Yan

1 GeV/u

0.2 GeV/u

Simpler charge distribution at higher energy

Z-Q

Z=60

Beta delayed neutron emission

Measurement of Pxn with Ring

A(Z,N) B(Z-1,N-X)

Xn

Heavy recoil detector

Neutron wall A(Z,N) C(Z-1,N)

Schottky detector

Forward neutron: Neutron wall Heavy decay product: charged particle detector/Shottky

Conventional Beta+neutron correlation is limited by the poor response to low energy neutron.

Internal target experiment z Boost beam current (108 particles,106 HzÆ max

effective intensity : 1014 pps) z Free of beam induced background z Ultra-thin target (1013 atoms/cm2)

Conventional target: 10 mg/cm2 Carbon foil Æ >1017 atoms/cm2

¾ Allow low energy particle escaping from the target

¾ Minimize beam particle energy loss in target

ITE Si array in UHV (EXL)

A case study 132Sn (T1/2=40 s)

z HIAF: 3.5E6 ppsÆstored ion: 2.2E8 particles Effective intensity: 2.2E14 pps z RIBF: 3E6 pps z FRIB: 1E8 – 1E9 pps z EURISOL: 4E11 pps z BEIJING ISOL(CARIF): 5E10 pps

Light ion induced direct reactions elastic scattering (p,p), (,), … nuclear matter distribution (r), skins, halo structures inelastic scattering (p,p’), (,’), … giant resonances, deformation parameters, B(E2) values, transition densities charge exchange reactions (p,n), (3He,t), (d, 2He), … Gamow-Teller strength transfer reactions (p,d), (p,t), (p, 3He), (d,p), … single particle structure, spectroscopic factors spectroscopy beyond the driplines neutron pair correlations nuclear structure relevant to nuclear reactions at stellar energy (ANC, energy, spin, Jp, decay branching ratio) knock-out reactions (p,2p), (p,pn), (p,p 4He)… ground state configurations, nucleon momentum distributions, cluster correlations Modified based on Egelhof’s talk

Production of n-rich isotopes at low energies

Fission products of 238U

Products of MNT reactions

Products of fusion reactions

The low-energy intense beams will enable producing very n-deficient nuclei by fusion reactions and particularly heavy and super-heavy n-rich nuclei by multi-nucleon transfer reactions.

z Synthesize new isotopes. z Measure the g.s. properties. z Build the decay schemes. zBuild a bridge to the island of SHN. z Simulate the rp and r processes. z Study the evolution of shell structure.

A/Z=2.7

A/Z=3.0

Production of Neutron Rich isotopes using MNT

Watanabe et al., PRL 115, 172503 (2015)

KISS project @ RIKEN N126 factory @ ANL GaLS@DUBNA T-Rex@TAMU...

MNT

Fragmentation

Properties of Super Heavy Nuclides

Island ?

¾Produce new elements and isotopes. ¾Gain insight into the mechanisms of fusion. ¾Measure masses and lifetimes.

¾Perform chemistry with the heaviest elements. ¾Hunt for new K-isomers. ¾Obtain information on the single particle states.

V. I. Zagrebaev et al. PRC 87, 034608 (2013)

Is there a limit, in terms of proton and mass numbers, to the existence of nuclei? Unprecedented opportunities for the synthesis of new isotopes and structure studies.

54Cr + 243Am 119* 55Mn + 243Am 120* 58Fe + 243Am 121*

Preliminary Results: ImQMD+HIVAP

K. Zhao (CIAE)

SHN factory

High intensity LINAC 28 pmA U E< 17 MeV/u

Stimulated by N126 @ANL

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Endpoint of the r-process

r-process ended by n-induced fission

(Z,A)

(Z,A+1)

(Z,A)

(Z+1,A)

(Z,A+1)

n-capture (DC) fission

b- fission fission

fission barrier

n-induced fission b-delayed fission spontaneous fission

or spontaneous fission

(different paths for different conditions)

(Goriely & Clerbaux A&A 348 (1999), 798

• Mass • Decay

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Beijing ISOL Production of more neutron rich nuclei

Good and easy fragments

91Kr 1.8 s

132Sn 39.7 s

Good and easy： Large yield Long half live Easy to separate

CARR

78Ni beam by 91Kr from reactor

With 7X1010pps 91Kr: 78Ni 103-4pps RIBF: 101pps

I. Tanihata, NIM B266(2008)4067

W. P. Liu et al., Science China August 2011 Vol.54 Suppl. 1: s14–s17

Summary • Chinese Nuclear Astrophysics community is

growing rapidly with strong support from government

• Need better interaction with JINA

• Need something like JINA to bring observation, modeling, nuclear experiment together and make better scientific contribution

http://custipen.pku.edu.cn/custipen_files/FRIB-China-Workshop_v6.pdf

HIAF@2023