Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada History of
A science fiction adventure story by Jess H. Brewer
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 1 Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada History of
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 1 OUTLINE
Early History of µSR (“science fiction”?)
Research “Themes” in µSR
Development of Advanced Muon Beams
µSR techniques (green: not invented at TRIUMF)
acronyms: wTF, ZF, LF, Strobo, FFT, SR, HTF, RRF, ALCR, RF, μSI, E-field (µSR applications interleaved among techniques...)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 1 Evolution of μSR : Fantasy ➜ Fiction ➜ Physics
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 3 Evolution of μSR : Fantasy ➜ Fiction ➜ Physics
Fantasy: violates the “known laws of physics”
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 3 Evolution of μSR : Fantasy ➜ Fiction ➜ Physics
Fantasy: violates the “known laws of physics”
Science Fiction: possible in principle, but impractical with existing technology. (Clarke’s Law: “Any sufficiently advanced technology is indistinguishable from magic.” )
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 3 Evolution of μSR : Fantasy ➜ Fiction ➜ Physics
Fantasy: violates the “known laws of physics”
Science Fiction: possible in principle, but impractical with existing technology. (Clarke’s Law: “Any sufficiently advanced technology is indistinguishable from magic.” )
Routine Physics: “We can do that . . .”
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 3 Evolution of μSR : Fantasy ➜ Fiction ➜ Physics
Fantasy: violates the “known laws of physics”
Science Fiction: possible in principle, but impractical with existing technology. (Clarke’s Law: “Any sufficiently advanced technology is indistinguishable from magic.” )
Routine Physics: “We can do that . . .” Applied Science: “ . . . and so can you!”
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 3 Before 1956: μSR = Fantasy (violates “known laws of physics”)
1930s: Mistaken Identity
Yukawa’s “nuclear glue” mesons ≠ cosmic rays 1937 Rabi: Nuclear Magnetic Resonance
1940s: “Who Ordered That?”
1944 Rasetti: 1st application of muons to condensed matter physics 1946 Bloch: Nuclear Induction (modern NMR with FID etc.) 1946 Various: “two-meson” π-µ hypothesis 1947 Richardson: produced π & µ at Berkeley 184 in. Cyclotron 1949 Kuhn: “The Structure of Scientific Revolutions”
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 4 2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 5 Before 1956: μSR = Fantasy (violates “known laws of physics”)
1930s: Mistaken Identity
Yukawa’s “nuclear glue” mesons ≠ cosmic rays 1937 Rabi: Nuclear Magnetic Resonance
1940s: “Who Ordered That?”
1944 Rasetti: 1st application of muons to condensed matter physics 1946 Bloch: Nuclear Induction (modern NMR with FID etc.) 1946 Various: “two-meson” π-µ hypothesis 1947 Richardson: produced π & µ at Berkeley 184 in. Cyclotron 1949 Kuhn: “The Structure of Scientific Revolutions”
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 6 Before 1956: μSR = Fantasy (violates “known laws of physics”)
1930s: Mistaken Identity
Yukawa’s “nuclear glue” mesons ≠ cosmic rays 1937 Rabi: Nuclear Magnetic Resonance
1940s: “Who Ordered That?”
1944 Rasetti: 1st application of muons to condensed matter physics 1946 Bloch: Nuclear Induction (modern NMR with FID etc.) 1946 Various: “two-meson” π-µ hypothesis Brewer: born 1947 Richardson: produced π & µ at Berkeley 184 in. Cyclotron 1949 Kuhn: “The Structure of Scientific Revolutions”
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 6 1956-7: Revolution
1950s: “Particle Paradise” culminating in weird results with strange particles:
1956 Cronin, Fitch, . . . : “ τ - θ puzzle” (neutral kaons) 1956: Lee & Yang postulate
P -violation in weak interactions
1957: Wu confirms P-violation in β decay;
Friedman & Telegdi confirm P-violation in π-µ-e decay;
so do Garwin, Lederman & Weinrich, using a prototype μSR technique.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 7 For newcomers . . . How does it work? . . . a brief intoducton t P
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 8 + + Pion Decay: π → µ + νµ A spinless pion stops in the “skin” of the primary production target. It has zero linear momentum and zero angular momentum. Conservation of Linear Momentum: The µ+ is emitted with momentum equal and opposite to that of the νµ . + Conservation of Angular Momentum: µ & νµ have equal & opposite spin.
Weak Interaction:
Only “left-handed” νµ are created.
Thus the emerging µ+ has its spin pointing antiparallel to its momentum direction. + + Pion Decay: π → µ + νµ A spinless pion stops in the “skin” of the primary production target. It has zero linear momentum and zero angular momentum. Conservation of Linear Momentum: The µ+ is emitted with momentum equal and opposite to that of the νµ . + Conservation of Angular Momentum: µ & νµ have equal & opposite spin.
Weak Interaction:
Only “left-handed” νµ are created.
Thus the emerging µ+ has its spin pointing antiparallel to its momentum direction. ✘ + μ Decay
Neutrinos have negative helicity, antineutrinos positive. An ultrarelativistic positron behaves like an antineutrino. Thus the positron tends to be emitted along the µ+ spin – + when νe and νµ go off together (highest energy e ).
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 10 Weak Transverse Field + (wTF)-µ SR (CW)
Typical time spectrum (histogram)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 11 1958-1973: Science Fiction
1960s: Fundamental Physics Fun! — Tours de Force Michel Parameters = Weak Interaction Laboratory
Heroic QED tests: AHF(Mu), µµ, gµ − 2 All lead to refined µSR techniques. Applications: Muonium Chemistry, Semiconductors, Magnetism
1972: Bowen & Pifer build first Arizona/surface muon beam to search for for µ+e− → µ−e+ conversion
mid-1970s: Meson Factories — Intensity Enables! USA: LAMPF (now defunct) Switzerland: SIN (now PSI) Canada: TRIUMF UK: RAL/ISIS Japan: KEK/BOOM ( → J-PARC)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 12 μSR today: Routine Science?
J-PARC
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 13 μSR today: Routine Science?
ESS J-PARC ★
SNS ★ ★ BNL RAON ★ CSNS ★
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 14 1972 ISIS site plan
Jess H. Brewer, UBC & TRIUMF — PSIColloquium atRing Ohio Univ. — 5 MayCyclotron 2006 OUTLINE 18 J-PARC synchrotron
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 15 CW vs. Pulsed µSR
“Advantage factor” for pulsed muons:
Ap = log(N in /N out)
Advantage of CW muons: time resolution (< 1 ns vs. > 10 ns) Disadvantage of CW muons: rate (< 104 s−1 vs. “unlimited”)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 16 TRIUMF CW vs. Pulsed µSR PSI
“Advantage factor” for pulsed muons:
Ap = log(N in /N out)
Advantage of CW muons: time resolution (< 1 ns vs. > 10 ns) Disadvantage of CW muons: rate (< 104 s−1 vs. “unlimited”)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 16 TRIUMF ISIS CW vs. Pulsed µSR PSI J-PARC
“Advantage factor” for pulsed muons:
Ap = log(N in /N out)
Advantage of CW muons: time resolution (< 1 ns vs. > 10 ns) Disadvantage of CW muons: rate (< 104 s−1 vs. “unlimited”)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 16 + Research “Themes” in µ SR
Muonium as light Hydrogen The Muon as a Probe (Mu = µ+e−) (H = p+e−) ! Probing Magnetism: unequalled sensitivity ! Mu vs. H atom Chemistry: - Local fields: electronic structure; ordering - gases, liquids & solids - Dynamics: electronic, nuclear spins - Best test of reaction rate theories. - Study “unobservable” H atom rxns. ! Probing Superconductivity: (esp. HTcSC) - Discover new radical species. - Coexistence of SC & Magnetism ! Mu vs. H in Semiconductors: - Magnetic Penetration Depth λ + - Until recently, µ SR → only data on - Coherence Length ξ metastable H states in semiconductors!
! Quantum Diffusion: µ + in metals (compare H+); Mu in nonmetals (compare H).
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 17 − And then there’s µ SR ...
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 18 − And then there’s µ SR ...
... but there’s not enough time for all its methods & applications.
:-(
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 18 µ+SR vs. µ−SR
Typical time spectrum (histogram)
Single lifetime τµ = 2.197 µs
Multiple lifetimes (some very short!)
Asymmetry spectrum
Large amplitudes
Small amplitudes due to cascade depolarization MUON BEAMS
+ − DECAY MUON CHANNEL (µ or µ )
π→µ decay section pµ analyzer
π
PROTON PROTON BEAM “Forward” µ pπ selector “Backward” µ . ~ 80% polarized . pµ ~ 65 MeV/c . Range: ~ 4±1 gm cm−2 .
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 20 Surface Muons a.k.a. “Arizona muons” + π : all energies & angles. (Bowen & Pifer, U. Ariz. 1973) spin µ+: 4 MeV, momentum 100% spin polarized
Range: 150±30 mg/cm2. Bright, imageable source. ~1 cm T1 Proton Beam Proton
Some pions stop in “skin” of production target & decay at rest.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 21 Moderated Muons
4 MeV μ+
(spin)
PSI: E. Morenzoni et al., PRL 72, 2793 (1994). ⬇ LEM facility now delivers ~4500 μ+/s to samples at 5-20 keV.
➜ study thin films!
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 22 Moderated Muons
4 MeV μ+
(spin)
TRIUMF: PSI: D.R. Harshman et al., PRL 56, E. Morenzoni et al., 2850 (1986). PRL 72, 2793 (1994). ⬇ ⬇ G.D. Morris, M.Sc. thesis (1989). LEM facility now ⬆ delivers ~4500 μ+/s to samples at 5-20 keV. Unfortunately, yield of 1.75(4) epithermal μ+ per 106 incident surface muons (for a solid Ar moderator) was too low to be practical at TRIUMF intensities. ➜ study thin films!
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 22 Laser-Ionize Thermal Muonium
RIKEN-RAL (UK): J-PARC (Japan):
Advantage for Pulsed beams: re-accelerated pulse is short ⇒ improved time resolution!
Low emittance ⇒ very small final focus! (“Microscope”)
➔ More LE-μSR
➔ Improved muon g−2
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 23 μ+ Stopping Luminosity
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 24 E ×B velocity selector & Spin Rotator ("DC Separator" or Wien filter) for surface muons:
Removes beam positrons
Allows TF-µ+SR in high field (otherwise B deflects beam)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 25 High Field µSR
Fields of up to 10 T are now available, requiring a “business end” of the spectrometer < 3 cm in diameter (so that 30-50 MeV decay positron orbits don’t “curl up” and miss the detectors) and a time resolution of ∼ 150 ps. Muonium precession frequencies of over 2 GHz have been studied.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 26 Type-II Superconductors
Vanadium at 0.16 T Fitting must always be done in the time domain, because of the “noise” from late times (low statistics).
Extract magnetic penetration depth λab (λab−2 ∝ ns).
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 27 Coexistence of SC & Magnetism
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 28 ZF /LF-µSR & Local Magnetic Fields
MnSi below 29 K: helimagnetic MnSi below 29 K: helimagnetic MnSi at 285 K: relaxation by static nuclear dipolar fields (PM moments flip too fast) Hayano et al. TRIUMF - 1979
5 K Decoupling by LF
Static Gaussian Kubo-Toyabe: g Gzz(t)
G 2 2 2 2 g zz(t) = [1 + 2(1 - Δ t )・exp(-Δ t /2)] / 3
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 29 ZF /LF-µSR & Local Magnetic Fields
MnSi below 29 K: helimagnetic MnSi below 29 K: helimagnetic MnSi at 285 K: relaxation by
... static nuclear dipolar fields (PM moments flip too fast) Hayano et al. TRIUMF - 1979
5 K Decoupling
veryinteresting by LF , things , get
Static Gaussian Kubo-Toyabe: g Gzz(t) In between In
G 2 2 2 2 g zz(t) = [1 + 2(1 - Δ t )・exp(-Δ t /2)] / 3
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 29 + Motion of μ Spins in Fluctuating Local Fields
“Strong Collision” model: local field is reselected at random from the same distribution each time a fluctuation takes place, either from muon hopping (plausible) or from reorientation of nearby moments (unlikely to change so completely).
Kehr’s recursion relation:
Sometimes solvable using Laplace transforms; numerical methods usually work too.
Used to extract “hop” or fluctuation rate ν.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 30 Time Scales
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 31 μSR Acronyms
Longitudinal Transverse Field Field Zero Field
Avoided Fourier Level Transform Crossing µSR Resonance
Muon Muon Spin Spin Resonance Echo
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 32 μSR Acronyms
Longitudinal Transverse Field Field Zero Field
Avoided Fourier Level Transform Crossing µSR Resonance
Muon Muon Spin Spin Resonance Echo
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 32 Finis Chronological List of Co-authors T. Masumoto F.J. Litterst M. Suzuki K.R. Kendall A.J. Berlinsky Z. Salman C. Michioka K.M. Crowe J. Doornbos K.W. Lay R.V. Upasani A. Adamczak K. Prsa R.F. Johnson B. Boucher J. T. Murakami H. Takagi A.R. Kunselman L.Y. Chiang W. Kang V.M. Bystritsky M. Laulajainen K. Yoshimura O.K. Forslund J.A. Macdonald Chappert A. Kulpa G.R. Mason T. Csiba C.V. Kaiser M. Isobe A. Schenck J.N. Ng S. Uchida P.M. Chaikin M.P. Faifman R.W. Williams A. Yaouanc S. Ohkuma S. Etemad A. Olin B.W. Lee G. Gruner N.P. Kherani A.T. Savici Y. Ueda D.R. Harshman O. Hartmann G. Roehmer T. Pfiz J.P. Franck H. Luetkens C. Michioka D.Ll. Williams S.E. Kohn D. Keane P.E. Armstrong S.K. Kim F.N. Gygax R.W. Wappling P. Schleger V. Lee P. Morin R.W. Ellis S. Harker M. Maier E. Morenzoni T. Noritake J.L. Smith V. Jaccarino S. Hikami I. Affleck M.C. Fujiwara S.F. Marenkin K. Miwa D.G. Fleming C.A. Fry J.B. Torrance A. Keren V.E. Markushin B.D. Patterson W.J. Kossler I. Ishikawa A.R. Strzelecki T. Hsu R.L. Whetten F. Mulhauser V.S. Melezhik O.N. Pashkova S. Towata R.F. Marzke B. Hitti B.J. Sternlieb A.H. O'Reilly B. Obradovic I. Tucakov M. Harada D.M. Garner M.J. Priestley J.E. Schirber S.M. Huang T.A. Porcelli A.E. Pifer J.R. Kempton D.E. Cox E.L. Venturini P.C.E. Stamp S. Lin Y. Zhang L.A. Schaller J. Cosman Y. Miyake W.S. Glaunsinger H.E. Schone R. Kadono H.R. Hart L. Brard A. Froese J. He T. Bowen, K.B. Rawlings B. Morosin R.B. Kaner V.A. Stolupin D.A. Delise X.H. Yu P. Mulhern D.S. Ginley S. Sun-Mack F. Diederich J.E. Fischer J.S. Gardner A. Lau I. Bredeson P. Van Rheenen C.E. Stronach M.A. Subramanian Y. Dalichaouch A.B. Smith III K. Mukai D. Hitchcock G.S. Clark M. McKelvy K.H. Chow S. Donovan K.F. Poon G.M. Marshall .W.F. Lankford J. Gopalakrishnan P. Dosanjh J.D. Garrett G. Gruner R.M. Strongin S.L. Stubbs D. Andreica D. Mandrus T. Hatano Y. Oonuki A.W. Sleight S. Shiratake J.E. Sonier A. Amato A. Gervellino J.B. Warren T. Natsui B. Gowe K. Holczer N.J. Curro K. Nagamine T. Komatsubara V.J. Emery M. Norman T. Tamegai D.G. Hinks H. Alloul H. Itahara T. Fujii Y. Sassa Y. Suzuki G. Aeppli A. Moodenbaugh Y. Iye G. Collin A. Asamitsu N. Egetenmeyer N. Nishida A. Hintermann P.W. Schleger J.D. Jorgensen T. Tani R.S. Hayano E. Bucher M. Suenaga C.L. Seaman R. Yoshizaki J.J. Boyle J.F. Marucco A.N. Price M. Janoschek O. Tjernberg W. Ruegg J.E. Crow D.C. Johnston A. Yamazaki S. Johnston B. Roessli G. Kobayashi T. Yamazaki W. Studer H. Zhou R.S. Cary H. Itahara R.A. Duncan J. Imazato B.X. Yang L.P. Le J. Akimitu R. Jacot-Guillarmod D.J. Arseneau K. Dohmae L. Keller R. Kanno A.J. van der Wal J.K. Furdyna D. Shimada H. Ueda S.L. Lee Y. Ando J.F. Bueno T. Takeuchi F. Stucki K. Kakurai P.E. Knowles C. Xia Y. Ishikawa J.M. Bailey M. Ishikawa Y. Tokura S. Katsuyama P. Kammel J. Rammer Y. Seno V. Pacradouni R. Bayes L. Schlapbach S.F.J. Cox D. Opie K. Kosuge A.N. Ismail S.A. Sabok-Sayr W. Faszer A. Ahktar M.J. Priestley B.R. Cyca J. Zmeskal B. Hitti H. Yasuoka K. Venkateswaran Y. Endoh H. Kojima P.M. Grant C. Petitjean S.J. Poon T. Motohashi X.F. Sun M.D. Hasinoff R. Keitel R.J. Cava E. Kudo M.E. Lopez-Morales S.P. Cottrell S. Komiya E.L. Mathie Y.C. Jean M. Senba I. Tanaka L. Schellenberg M. Karppinen R.J. Mikula J.F. Carolan K. Yamada M.R. Davis J.J. Neumeier B. Pippitt N.V. Prokof'ev M. Bayer W.A. Atkinson R.E. Mischke E.J. Ansaldo W.N. Hardy D.C. Johnson G. Saito S.R. Dunsiger P.L. Russo K. Olchanski L.C. Vaz Z. Fisk H.K. Yen Y. Ajiro S. Hirano D.C. Walker R. Krahn M. Alverez Y. Tokura S. Kubono M. Mekata D.G. Eschenko S. Eggert I. Watanabe V. Selivanov S. Lambert R.C. Thompson D.P. Goshorn T. Nomura M. Montour K. Ariyoshi R. Tacik C.J. Martoff M.S. Torikachvili C.L. Chien J. Sugiyama M. Verdaguer S.S. Rosenblum A.C.D. Chaklader Y. Hidaka M.Z. Chieplak H. Yamochi I. Shinkoda J.A. Chakhalian M. Mikami T. Ohzuku O. Sukhorukov M.B. Maple B. Batlogg M. Oda H. Keller R.I. Miller D.C. Peets S.L. Mielke D.P. Spencer Y. Miyake G. Xiao H. Gluckler Y. Mori R.F. Kiefl H. Miyatake Y. Enomoto B.W. Statt W. Kundig H. Yamauchi A. Wong T. Sasaki A.A. Nikonov D.G. Truhlar Y. Tabata D. Shiada M. Suzuki I.M. Savic J.W. Brill O.E. Parfenov G.C. Schatz C.J. Oram K. Ishida U. Naerger S. Tanaka H. Nozaki D.J. Judd S. Okuma T. Murakami J.L. Booth H. Simmler T.L. Duty M.F. White Jr. H. Hazama I. Terasaki B.C. Garrett T. Matsuzaki M. Ishawa A. Kulpa B. Stauble-Pumpin R. Cywinski T. Goko K.A. Peterson L.D. Spires K. Nishiyama L.A. Whitehead W.A. MacFarlane R. Asahi R.I. Grynszpan T. Takabatake S. Ohkuma E.H. Wishnow M. Warden J.W. Elzey R.H. Heffner Y. Ono R. Jin Y. Doi D.R. Noakes Y. Nakazawa G. Roehmer D. Zech J. Bermejo H. Sha Y. Hinatsu A.T. Stewart B.V.B. Sarkissian D.A. Balzarini P. Mendels T. Kajitani S. Talbot-Besnard T.M. Riseman P. Schleger C.C. Blake P. Zimmermann J.E. Fischer J.D. Brewer F.D. Callaghan J. Zhang R. Hu S.R. Kreitzman Y. Watanabe S. Hikami E. Kaldis D. Cowperthwaite T.G. Aminov C. Petrovic D.S. Beder S.E. Lambert L.L. Miller V.G. Storchak E. Boaknin C.W. Clawson N. Kaplan I. Ishikawa E.A. Early J. Karpinski B.F. Kirillov M.A. Clarker- L. Taillefer V.P. Zlomanov H. Zhou Y. Kuno M.E. Hayden B.J. Sternlieb S. Rusiecki Gayther A.A. Vinokurov Ch.R. Wiebe B.W. Ng E. Torikai J.T. Markert A.V. Pirogov S. Hebert Y. Ito B.X. Yang D.E. Cox P. Gehring J.W. Schneider V.A. Duginov J.S. Lord A. Maignan R.L. Kallaher Y. Higuchi H. Shirakawa D. Shimada R. Kadono Y. Maeno V.N. Gorelkin S. von Molnar I. Umegaki T. Suzuki R.E. Turner Y. Yamada V.G. Grebinnik B.A. Aronzon P.W. Percival M. Ishikawa P. Mulhern T.R. Thurston C. Rossel T.N. Mamedov P. Amaudruz T. Takami A.A. Bush W. Higemoto S.A. Dodds D. Opie M.A. Subramanian W. D. Wu R. Baartman O. Ofer T.-H. Kao J.A.R. Coope T.L. Estle R.J. Birgeneau V.G. Ol'shevsky H. Ikuta E. Koster Y. Endoh J. Gopalakrishnan Q. Li H.H. Wang V.A. Zhukov J. Behr U. Mizutani M. Mansson H.-D. Yang G.A. Gist E. Kudo A.W. Sleight A.M. Kini S. Daviel H. Sakurai A.M. Tokmachev H. Schilling Q. Zhu K. Hepburn-Wiley B. Hunter C. Delmas E.E. Haller K. Yamada V.J. Emery R.C. DuVarney J.M. Williams K.N.R. Taylor T. Kuo A.M. Froese E. Takayama- S.N. Barilo S.L. Rudaz D.C. Johnson M. A. Moodenbaugh S. Ishibashi C.D.P. Levy Muromachi M. Imai R. Nakai M. Celio R.L. Lichti D.A. Bonn B.A. Fryer M. Doyama Alverez M. Suenaga C. Schwab G.D. Morris R. Liang M. Olivo K. Ghandi K. Kamazawa C. Baines G.M. Luke D.P. Goshorn D.C. Johnston Ch. Niedermayer R. Poutissou V. Sikolenko S. Kobayashi R. Yamamoto H.S. Chen B.M. Forster D.J. Baar Y. Ikedo Y.J. Uemura Y. Hidaka A.J. Jacobson G.A. Beer E.P. Krasnoperov D.C. Morgan G.W. Wight K. Mukai V. Pomjakushin I. Zivkovic G.M. Kalvius M. Oda J.T. Lewandowski E.E. Meilikhov A. Zelenski H. Sakurai H.T. Yi C.Y. Huang L. Asch J.L. Beveridge K. Zhang H. Yoshida A.M. de Graff Y. Enomoto H. Hart T.M. Huber V.P. Smilga C. Kallin E. Karlsson Z. Hiroi H. Ohta S.-W. Cheong
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 34 Avoided Level-Crossing Resonance
μ+ in Cu, LF, 20K
Nuclear Quadrupolar version
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 35 Avoided Level-Crossing Resonance
μ+ in Cu, LF, 20K
Nuclear Quadrupolar version
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 35 Avoided Level-Crossing Resonance
e.g. CuCl semiconductor
Nuclear Hyperfine (SIN) version
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 36 Muonated Radicals
Organic Free Radicals in Superheated Water Paul W. Percival, Jean-Claude Brodovitch, Khashayar Ghandi, νµ Brett M. McCollum, and Iain McKenzie
Apparatus has been developed to permit muon avoided level- A crossing spectroscopy (µLCR) of organic free radicals in water at high temperatures and pressures. The combination of µLCR with transverse-field muon spin rotation (TF-µSR) provides the means to identify and characterize free radicals via their nuclear hyperfine constants. Muon spin spectroscopy is currently the only technique capable of studying transient free radicals under hydrothermal conditions in an unambiguous manner, free from interference from other reaction intermediates. We have utilized the technique to investigate hydrothermal chemistry in two areas: dehydration of alcohols, and the enolization of acetone. Spectra µALCR have been recorded and hyperfine constants determined for the following free radicals in superheated water (typically 350°C at 250 bar): 2-propyl, 2-methyl-2-propyl (tert-butyl), and 2- hydroxy-2-propyl. The latter radical is the product of muonium addition to the enol form of acetone and is the subject of an earlier publication. The figure shows spectra for the 2-propyl radical detected in an aqueous solution of 2-propanol at 350°C and 250 bar.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 37 RF-µSR : muon Spin Resonance
Resonance at ωµ shows fraction of muons in diamagnetic states such as Mu+ (= “bare” µ+), Mu− in various lattice sites even if it began as a paramagnetic state like Mu. Used to study formation and dissociation.
Muonium resonance at ωij shows fraction of muons in paramagnetic states such as Mu itself or a radical (paramagnetic molecule). In the above case the field-sweep shows broad ω12 and ω23 resonances as well as a sharp two-photon resonance at their average.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 38 RF-µSE : muon Spin Echo
⬅ Direct µSE in LaF3: muons enter with spins along B0. A Π/2 RF pulse at ωµ “flips them up” and they precess and “dephase”; a Π pulse at time τ makes them “refocus”.
Indirect µSE: muon spins initially ⊥ B0 are refocused by a Π pulse on the 19F nuclei at frequency ωF. ⬇
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 39 µSI : Muon Spin Imaging
“µ” cut from Al Magnetic field gradients applied in on depolarizing many directions; each spectrum substrate: Fourier transformed to translate frequency into spatial coordinates; all combined to form image:
Deemed impractical at TRIUMF; but with RF & gradient pulse sequences at a high intensity pulsed facility, who knows...? N. Kaplan et al., Hyperfine Int. 85, 271 (1994)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 40 Rotating Reference Frame
Muon spin precession in high transverse field (HTF-μSR) requires progressively smaller time bins to record the oscillations. These smaller bins capture fewer counts (lower statistics) and require more calculations for fitting. Worse yet, the essential characteristics of the data are not readily observed “by eye”. Lab Frame at 0.3668 T
Fortunately, it is easy to convert the asymmetry spectrum into a Rotating Reference Frame (RRF) after the fact.
Lab Frame at 0.2 T
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 41 Stroboscopic µSR
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 42 Stroboscopic µSR Schenck et al. - SIN
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 42 + − Muonium (Mu≡μ e ) and FFT Spectroscopy
In a µSR experiment one measures a time spectrum at a given field and extracts all frequencies via FFT.
A μ A νµ Larmor frequency
+ − “Signature” of Mu (or other hyperfine-coupled μ e spin states) in high transverse field: two frequencies centred on νµ and separated by the hyperfine splitting A∝r −3.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 43 Motion of Muon Spins = Expectation value of a S in Static Local Fields µ muon's spin direction
(a) All muons "see" same field B : for B || Sµ nothing happens
ω = 2π γ |B | µ µ for B ⊥ Sµ Larmor precession: ωµ γµ = 135.5 MHz/T
(b) All muons "see" same |B | but random direction :
2/3 of Sµ precesses at ωµ
1/3 of Sµ stays constant
(c) Local field B random in both magnitude and direction:
All do not return to the same orientation at the same time (dephasing) ⇒ Sµ "relaxes" as Gzz (t ) [Kubo & Toyabe, 1960's] Motion of Muon Spins = Expectation value of a S in Static Local Fields µ muon's spin direction
(a) All muons "see" same field B : for B || Sµ nothing happens
ω = 2π γ |B | µ µ for B ⊥ Sµ Larmor precession: ωµ γµ = 135.5 MHz/T
(b) All muons "see" same |B | but random direction :
2/3 of Sµ precesses at ωµ
1/3 of Sµ stays constant
(c) Local field B random in both magnitude and direction:
All do not return to the same orientation at the same time (dephasing) ⇒ Sµ "relaxes" as Gzz (t ) [Kubo & Toyabe, 1960's] Quantum Diffusion
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 45 Quantum Diffusion
Thermally activated over- barrier hopping (incoherent). ⬆ hot Phonon scattering “spoils” coherent delocalization of lattice polarons. ⬆ warm Delocalized states find dilute defects and trap. ⬇ cold
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 45 Avoided Level-Crossing Resonance Nuclear Quadrupolar version: MnSi
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 46 Radiolysis & “Delayed” Muonium Formation
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 47 Radiolysis & “Delayed” Muonium Formation
Possible exceptions: solids with extremely high electron mobilities.
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 47 2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 48 Muonium Formation in an Electric Field
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 49 Delayed Mu Formation in Cryocrystals (e.g. s-N2)
Muonium fraction
Diamagnetic fraction (µ+)
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 50 “Ordinary” Solids: Insulators & Semiconductors Note different horizontal & vertical scales!
‹Reµ› ≈ 40 nm
‹Reµ› ≈ 15 nm
‹Reµ› ≈ 20 nm
‹Reµ› ≈ 60 nm Weakly Bound Mu States in High-Mobility Semiconductors
Initial states Muwb GaAs have electron GaP orbitals “out in the lattice” with different effective masses; those with higher m* are more strongly bound and harder to ionize with an applied E field.
V.G. Storchak et al., Phys. Rev. B 67, 121201 (2003).
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 52 Weakly Bound Muonium States in GaAs & GaP
V.G. Storchak, D.G. Eshchenko, R.L. Lichti and J.H. Brewer
Muonium formation via electron transport to a positive muon implanted into semi-insulating GaP has been studied using muon spin rotation/ GaAs relaxation with alternating electric fields up to 160 kV/cm. Formation of the GaP muonium ground state is prohibited by a characteristic electric field of about 50 kV/cm in GaP compared to 5 kV/cm in GaAs, implying that formation of the less Mu Mu ground state may proceed through more Mu a weakly-bound intermediate state with a binding energy of about 23 meV in GaP or 7 meV in GaAs. These results are discussed and justified within the effective mass model.
See µSR Literature Entry # 2437
Phys. Rev. B 67, 121201 (2003).
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 53 Weakly Bound Muonium States in GaAs & GaP
V.G. Storchak, D.G. Eshchenko, R.L. Lichti and J.H. Brewer
Lighter effective mass & higher mobility e − ⇒ Muonium formation via electron easier to prevent Mu formation by applied E. transport to a positive muon implanted into semi-insulating GaP has been studied using muon spin rotation/ GaAs relaxation with alternating electric fields up to 160 kV/cm. Formation of the GaP muonium ground state is prohibited by a characteristic electric field of about 50 kV/cm in GaP compared to 5 kV/cm in GaAs, implying that formation of the less Mu Mu ground state may proceed through more Mu a weakly-bound intermediate state with a binding energy of about 23 meV in GaP or 7 meV in GaAs. These results are discussed and justified within the effective mass model.
See µSR Literature Entry # 2437
Phys. Rev. B 67, 121201 (2003).
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 53
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 54
Jess H. Brewer, UBC & TRIUMF — Colloquium at Ohio Univ. — 5 May 2006 OUTLINE 7 ⇥
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 55
Jess H. Brewer, UBC & TRIUMF — Colloquium at Ohio Univ. — 5 May 2006 OUTLINE 8 Coordinate Conventions
2019 June 3-7 at Simon Fraser U. Congress of the Canadian Association of Physicists - History of Physics (DHP) 56