a proposed muon facility at raon/koreaparticle.korea.ac.kr/news/usm2013_risp_final.pdf · 2013. 9....

Aug. 9-12, 2013 International Symposium on Science Explored by Ultra Slow Muon Eunil Won, Physics Department, Korea University

A proposed muon facility at RAON/Korea

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A proposed muon facility at RAON/Korea

Eunil WonKorea University

International Symposium on Science Explored by Ultra Slow Muon, Aug. 9-12, 2013

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Contents

• A new accelerator under construction in Korea

• A proposal on a muon facility

✓ Ongoing work for a μSR facility design

✓ R&D for a charged lepton flavor violation experiment

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RISP or RAON• RISP: Rare Isotope Science Project (RISP) of Institute

for Basic Science (IBS) is a part of ISBB program to build a heavy ion accelerator, “RAON” for rare isotope science researches in Korea

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• RAON: “라온”

- pure Korean word meaning Delightful, Joyful, Happy




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- pure Korean word meaning Delightful, Joyful, Happy with a wish that this accelerator would be a delightful gift for scientists all

over the world and for the bright future of mankind.




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- pure Korean word meaning Delightful, Joyful, Happy with a wish that this accelerator would be a delightful gift for scientists all

over the world and for the bright future of mankind.

• KoRIA: Korea Rare Isotope Accelerator


A Brief History of RISP

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• ISBB plan (2009.1) • Preliminary Design Study (2009.3-2010.2)• Conceptual Design study (2010.3-2011.2)• International Advisory Committee (2011.7)• Institute for Basic Science(IBS) established (2011.11)

• Rare Isotope Science Project (RISP) launched (2011.12)• 1st RISP Workshop on Accelerator Systems (2012.5)• 1st Technical Advisory Committee (2012.5)• Baseline Design Summary (2012.6)• International Advisory Committee (2012.7)• KoPAS (Particle Accelerator School) (2012.12)• 2nd RISP Workshop on Accelerator Systems (2013.5)• 2nd TAC (2013.5)

• Technical Design Report (2013, summer)



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• ISBB plan (2009.1) • Preliminary Design Study (2009.3-2010.2)• Conceptual Design study (2010.3-2011.2)• International Advisory Committee (2011.7)• Institute for Basic Science(IBS) established (2011.11)

• Rare Isotope Science Project (RISP) launched (2011.12)• 1st RISP Workshop on Accelerator Systems (2012.5)• 1st Technical Advisory Committee (2012.5)• Baseline Design Summary (2012.6)• International Advisory Committee (2012.7)• KoPAS (Particle Accelerator School) (2012.12)• 2nd RISP Workshop on Accelerator Systems (2013.5)• 2nd TAC (2013.5)

• Technical Design Report (2013, summer)

Available from http://risp.ibs.re.kr

http://risp.ibs.re.kr

http://risp.ibs.re.kr


Science @ RISP

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History of Elements Discovery

6Source: B. Sherrill (Mathematica+Wikipedia)



6Source: B. Sherrill (Mathematica+Wikipedia)

Cooper Age

IndiaBabyloniaEgyptChina

Democritus- Ideas of Atoms

1700+ rise of modern chemistry



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Times of alchemist

Chemistry, Dalton’s atomic theoryCavendish, Priestly, Scheele, ... Mendeleev’s

Periodic Table

Source: B. Sherrill (Mathematica+Wikipedia)



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Times of alchemist

Chemistry, Dalton’s atomic theoryCavendish, Priestly, Scheele, ... Mendeleev’s

Periodic Table

Particle Accelerators

Source: B. Sherrill (Mathematica+Wikipedia)


Origin of Elements

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Abundance of atoms

http://homepages.ius.edu/kforinas/CalssRefs/modern.html




Origin of Elements

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Abundance of atoms• Light elements are dominated (log scale!)





Origin of Elements

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Abundance of atoms• Light elements are dominated (log scale!)


✓ Where are they all from? ✓ Why is abundance so asymmetric?




Origin of Elements

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What we know so far...


Origin of Elements

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What we know so far... • Light elements were produced by Big-Bang (Big-Bang Nucleosynthesis)


Origin of Elements

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• Heavy elements up to Fe were produced by nuclear fusion in Stars


Origin of Elements

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• Elements heavier than Fe were produced by consecutive capture of neutrons followed by beta decays (in violent astronomical processes such as Supernova explosion) s-process, r-process still to be understood!


Origin of Elements

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• Elements heavier than Fe were produced by consecutive capture of neutrons followed by beta decays (in violent astronomical processes such as Supernova explosion) s-process, r-process still to be understood!

One of main research topics at RISP


The Nuclear Landscape

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Chart of Nuclides (sometimes called a Segre Plot or Segre Chart)

Black squares are the around 260 stable isotopes found in nature (> 1 Gy)

Green closed are is the region of isotopes observed so far


Science/applications

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✓Nuclear Physics• Exotic nuclei near the neutron drip line • Superheavy Elements• Equation of state of nuclear matter• Nuclear structure



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✓Material Science• μSR/β-NMR• Production & Characterization of new materials



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✓Particle/Atomic physics• Charged lepton flavor violation/Symmetry• EDM/Atomic trap



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✓Particle/Atomic physics• Charged lepton flavor violation/Symmetry• EDM/Atomic trap

✓Nuclear Astrophysics• Origin of nuclei• Paths of nucleosynthesis• Neutron stars and supernovae

✓Medical and Bio sciences • Advanced therapy technology• Mutation of DNA• New isotopes for medical imaging

✓Nuclear data with fast neutrons• Basic nuclear reaction data for future nuclear energy• Nuclear waste transmutation



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✓Particle/Atomic physics• Charged lepton flavor violation/Symmetry• Atomic trap

✓Nuclear Astrophysics• Origin of nuclei• Paths of nucleosynthesis• Neutron stars and supernovae

✓Medical and Bio sciences • Advanced therapy technology• Mutation of DNA• New isotopes for medical imaging

✓Nuclear data with fast neutrons• Basic nuclear reaction data for future nuclear energy• Nuclear waste transmutation


Production of Rare Isotope Beam

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ISOL(Isotope Separator On-Line)p to thick target (eg. Uranium Carbide) : target spallation or fission (low energy)

RI Ions Re-acceleration

Stopping

RI Ion Beam

RI Beam

Stopped Beam experiment (Traps)

Fast Beam experiment

IF(In-Flight Fragmentation)Stable heavy ion beam → thin target → projec/le fragmenta/on (high energy)


Production of Rare Isotope Beam

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ISOL(Isotope Separator On-Line)p to thick target (eg. Uranium Carbide) : target spallation or fission (low energy)

RI Ions Re-acceleration

Stopping

RI Ion Beam

RI Beam

Stopped Beam experiment (Traps)

Fast Beam experiment

IF(In-Flight Fragmentation)Stable heavy ion beam → thin target → projec/le fragmenta/on (high energy)

RISP has unique capability of producing RI in both ways


Worldwide Existing/Planning Isotope Accelerator

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B. Sherrill


RAON Site

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• It is located to near Daejeon (~1 hour from Seoul by KTX)

We are hereDaejeon


Concept of RAON

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Aug. 9-12, 2013 International Symposium on Science Explored by Ultra Slow Muon Eunil Won, Physics Department, Korea University17

KPS 2012 (YKKIM/IBS)


A proposed muon facility at RAON

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• “We” are proposing a muon facility at RAON

• Who are “we”?

A small group of high energy physicists who are interested in both μSR and charged lepton flavor violation experiments.


Micro-Beam structure of RAON

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Continuous beam (for proton, 600 MeV/660 μΑ):- At RISP the accelerator structure (80 MHz microstructure) and the pion lifetime (26 ns) leads to a practically continuous surface muon beam

- But since one has to correlate incoming muon+ and the decay positron, one muon at a time to the sample should be achieved (otherwise it is background)

80 MHz = 125 ns

200 ps: from private communication with E. S. Kim @RISP/KNU


Micro-Beam structure of RAON

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Continuous beam:

- At RISP the accelerator structure (80 MHz microstructure) and the pion lifetime (26 ns) leads to a practically continuous surface muon beam

- But since one has to correlate incoming muon+ and the decay positron, one muon at a time to the sample should be achieved (otherwise it is background)

http://people.web.psi.ch/morenzoni/FS-2012/Chapter5-MuonSpinRotation-1.pdf




Continuous vs. Pulsed

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Pulsed beam:

- At a pulsed machine all the muons are contained in a pulse (50-100 ns wide) with low repetition rate (25-50 Hz)

- This allows a higher rate (all the decay positrons of a pulse are measured at once)

- But only one positron in a detector or in the case of more than one, you have to get the time stamp on them

: such as J-PARC facility


It will be extremely beneficial if we have one continuous and one pulsed μSR facilities in Asian region !


Muon Facility @ RAON

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μSR facility to be located here

Muon meeting 2013.05JHLee/RISP


Muon Facility @ RAON

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3600 cmMuon meeting 2013.05

JHLee/RISP✓ Place is secured✓ Budget is not yet


Muon facility R&D

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Muon production/transport/moderation

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- We are at early stage of conceptual design

Muon production

~10-5 surface muons/proton

Muon transport

ε(transport)~O(0.6-0.8)ε(collection)~O(3x10-2)

4x1015 protons/s

~104 thermalized muons/s

(660 uA)

(moderation: 10-5)

But don’t take this number too seriously yet


Ultra slow muon transport R&D- Einzel lens design simulation (CST)

Kyungmin Lee, Jihoon Choi/KU

- Result of simulation after field map into Geant4 (using PSI tool)

Moderated muons come in

: unit (mm)

ByeongRok Ko/KU


Fundamental muon physics @ RAON

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- Some of us have been looking at a muonium oscillation experiment (but not limited to it)

- Various new fundamental interaction can cause Mu to anti-Mu transition

Phys. Rev. Lett. 82, 49 (1999)

- Not updated since 1999

- A new technique to reject accidental and irreducible backgrounds more effectively needed



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arXiv:1307.5787 “Charged Lepton Flavor Violation: An Experimenter’s Guide” - by R. Bernstein and P. Cooper (Fermilab) - excellent review of cLFV experiments



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Latest limit: Phys. Rev. Lett. 82, 49 (1999)- typical counter type- suffer from rate-dependent background- < 3x10-3 GF was achieved



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M. Aoki, NIM A 503, 258 (2003)- a radiochemical approach- antimuonium absorbed in tungsten nucleus (μ- W →νμ 184Ta)- < 10-4 GF can be possible



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M. Aoki, NIM A 503, 258 (2003)- a radiochemical approach- antimuonium absorbed in tungsten nucleus (μ- W →νμ 184Ta)- < 10-4 GF can be possible

arXiv:1307.5787- improve counter type experiment- use modern technology- could reduce limit by 10-2 (but with pulsed beam)



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One slide R&D status

40 MeV e- in Xenon gas (atm)

10 MeV

8 MeV 4 MeV

Geant4 study for tracker is ongoing

✓ Improvement from CsI and faster timing

✓ Improvement from MWPC

✓ Muonium production R&D is starting with J-PARC people

✓ Active target ?


Summary

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Summary

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• A new accelerator under construction in Korea

• A proposed muon facility is described

✓ Conceptual design work for a μSR facility in progress

✓ R&D for a fundamental muon physics experiment is started

• One pulsed in Japan and one continuous μSR facility will be complementary and extremely beneficial to all of us

a proposed muon facility at raon/koreaparticle.korea.ac.kr/news/usm2013_risp_final.pdf · 2013. 9....

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