C R E S A N E W M E T H O D T O WA R D S M E A S U R I N G T - PowerPoint PPT Presentation

C R E S — A N E W M E T H O D T O WA R D S 
 M E A S U R I N G T H E 𝜉 - M A S S S E B A S T I A N B Ö S E R 7 T H J U N E 2 0 1 6 | G D R N E U T R I N O 2 0 1 6 | G R E N O B L E

M E A S U R I N G 𝜉 - M A S S Project8 — 2

T R I T I U M B E TA - D E C AY 3 H → 3 He + + e - + 𝜉 ̅ e • Sum of masses and kinetic energy must add 
 up to mass of initial nucleus Project8 — 3

T R I T I U M B E TA - S P E C T R U M dN q ( E − E 0 ) 2 − m 2 dE ∼ F ( Z, E ) p e ( E + m e ) β ) Project8 — 4

T R I T I U M B E TA - S P E C T R U M ✓ ◆ ( E − E 0 ) 2 − 1 dN 2 m 2 dE ∼ F ( Z, E ) p e ( E + m e ) β ) Endpoint of spectrum changes with 𝜉 -mass 
 → direct measurement of mass 
 (independent of “nature” of mass) Project8 — 5

T R I T I U M B E TA - S P E C T R U M • Fraction of e − in ROI • 10 eV: 2 × 10 − 10 1 eV: 2 × 10 − 13 • • Requirements • high count rate • high resolution Endpoint of spectrum changes with 𝜉 -mass 
 → direct measurement of mass 
 (independent of nature of mass) Project8 — 6

S TAT E O F T H E A R T — K AT R I N Key component: MAC-E filter • align e - momentum p ? → p k Project8 — 7

K AT R I N Karlsruhe Trititum Neutrino Experiment Sensitivity goal • m β < 200meV Limited by • size of spectrometer • systematic effects ➔ need a new and 
 Inverted hierarchy complementary approach Normal hierarchy Project8 — 8

C Y C L O T R O N R A D I AT I O N Cyclotron radiation eB ⊥ f c = 1 m e 2 π relativistic correction f γ = f c eB ⊥ γ = 1 m e + E kin 2 π “ Never measure anything but frequency ” - A. L. Schawlow Project8 — 9

R E S O L U T I O N Energy resolution 
 f ⋅ Δ E/E ~ Δ f • Δ E/E ~ 1eV / 511 keV = 2ppm 
 → easy! Frequency resolution 
 Δ f ~ 1/ Δ t • Δ t = 20 μ s ~ 1400m @ 18keV 
 → hard! A. L. Schawlow Project8 — 10

Idea • fill volume with 3 H gas • add magnetic field • decay electrons spiral around field lines • add antennas to detect cyclotron radiation B. Monreal and J. Formaggio, Phys. Rev D80:051301 Project8 — 11

F R E Q U E N C Y S C A L E magnetic field of 1T → cyclotron frequency in K-Band 83m Kr provides electrons close to tritium endpoint Project8 — 12

R A D I AT E D P O W E R Larmor formula q 4 B 2 1 2 ( γ 2 − 1) sin 2 θ P ( γ , θ ) = 4 πε 0 3 m 2 e p e Emitted power θ → pitch angle • 1.1 fW for 18 keV e - at 90º B-field • 1.7 fW for 30.4 keV e - at 90º → Low-noise cryogenic RF-system needed! Project8 — 13

P R O J E C T 8 P R O T O T Y P E Signal Project8 — 14

WAV E G U I D E C E L L Project8 — 15

S I G N A L A M P L I F C AT I O N A N D N O I S E fine Swedish 
 Noise temperature: T eff = 150K amplifier • Primary background 
 → thermal noise from waveguide and amplifiers Project8 — 16

R E C E I V E R S TA G E • Double-stage down-mixing • Digitizer: 8-bit, 500Ms/s, 125MHz bandwidth 
 → untriggered Project8 — 17

M A G N E T I C B O T T L E 1 + cot 2 θ ✓ ◆ f γ = f c eB γ = 1 Harmonic e - trap → 2 π m e + E kin 2 5mT Different 
 pitch angles Magentic 
 bottle coil Effect of trap on measured frequency easily calculable! Project8 — 18

E X P E C T E D S I G N A L Spectrogram • time slices 
 → consecutive 
 power spectrum Signal • narrow-band 
 → horizontal line • energy loss by radiation 
 → line is tilted Project8 — 19

A C T U A L S P E C T R O G R A M Data Taking on 06/06/2014 immediately shows trapped electrons PhysRevLett.114.162501 (2015) First detection of single-electron cyclotron radiation! Project8 — 20

S P E C T R O G R A M I N F O R M AT I O N Project8 — 21

E N E R G Y S P E C T R U M Initial frequency determines initial energy Project8 — 22

F I R S T E N E R G Y S P E C T R U M Both 83m Kr lines 
 → clearly seen Resolution • FWHM: 140 eV Phys. Rev. Lett. 114, 162501 (2015) Project8 — 23

I M P R O V E D T R A P Shallower Harmonic trap • better field uniformity • smaller acceptance → lower rate & 
 better resolution Bathtub trap • two coils at end of cell • better uniformity • larger trap size → larger rate & 
 better resolution Project8 — 24

C R E S — C Y C L O T R O N R A D I AT I O N 
 E M I S S O N S P E C T R O S C O P Y Hardware 
 improvements • better field 
 uniformity • reduced 
 noise level • better 
 temperature 
 stability Project8 — 25

P O T E N T I A L 𝜉 - M A S S R E A C H σ (B) ~ 0.1ppm, 1 year of data per cm 3 per cm 3 per cm 3 per cm 3 Sensitivity limited by gas density! Project8 — 26

P O T E N T I A L 𝜉 - M A S S R E A C H current cell 
 volume current limit per cm 3 per cm 3 inverted hierarchy bound per cm 3 Inverted hierarchy limit in reach with atomic tritium! Project8 — 27

P R O J E C T 8 
 C O L L A B O R AT I O N T. Thümmler Karlsruhe Institute of Technology S. Böser, C. Claessens * Johannes Gutenberg-Universität, Mainz K. Kazkaz Lawrence Livermore National Laboratory J. Formaggio, N. Oblath, E. Zayas * Massachusetts Institute of Technology * indicates graduate student M. Guigue, A. M. Jones, J. Tedeschi, B. VanDevender Pacific Northwest National Lab S. Doelman, J. Weintroub, A. Young Smithsonian Astrophysical Observatory K. Heeger, L. Saldana*, P. Slocum L. de Viveros, B. LaRoque * , B. Monreal Yale University University of California, Santa Barbara P. Doe, A. Ashtari Esfahani * , M. Fertl, E. Machado * , R.G.H. Robertson, L. Rosenberg, G. Rybka University of Washington, Center for Experimental Nuclear Physics and Astrophysics Project8 — 28

A P H A S E D A P P R O A C H P h a s e Ti m e l i n e S o u rce R & D M i le s to n e s S c i e n ce G o al s COMPLETED s i ng le e le ct ro n co n v ers i o n e le ct ro n I 2 0 1 0 -2 0 16 8 3 m K r d e t e ct i o n s p e ct r um o f 8 3 m K r p ro o f o f co n ce p t F i n al - s t at e s p e ct r um t e s t Ku r i e p lot I I 2 0 1 5 -2 0 1 7 T 2 3 H - 3 H e m a s s d iff ere n ce s y s te m at i c s t u d i e s m 𝜉 < 1 0 - 1 0 0 eV/c 2 h i g h - r at e s e n s i t i v i t y I I I 2 0 16 -2 0 2 0 T 2 m 𝜉 < 2 eV/c 2 B- F i e l d m a p p i ng m 𝜉 < 4 0 m eV/c 2 ato m i c t r i t i um I V 2 0 1 7 … T s o u rce m e a s u re m 𝜉 o r d e t e r m i n e no r m al h i er arc hy Project8 — 29

P H A S E - I I : T R I T I U M Improved insert installed • first 83m Kr data available → very promising • T 2 - system ready to be installed Project8 — 30

P H A S E I I I - L A R G E V O L U M E Example antenna configuration and vertex resolution being modeled • Larger bore ~1T magnet → exists • Phased array antenna configurations 
 → under study Project8 — 31

M O L E C U L A R T R I T I U M L I M I TAT I O N S Molecular excitations 
 ( 3 HeT) + in daughter molecule ( 3 HeH) + • blur tritium endpoint → fundamental limit 
 to measurement 
 of 𝜉 -mass Need atomic tritium for ultimate experiment! Advances in High Energy Physics 2013 (2013) 39 Project8 — 32

P H A S E I V: AT O M I C T R I T I U M Studying Ioffe-Pritchard trap • couple to nuclear magnetic moment µ · ~ ∆ E = − ~ B • similar to BEC and anti- hydrogen traps (ALPHA) Challenges • cool atomic tritium 
 to sub-Kelvin • need high T/T 2 purity Alexi Radovinsky, MIT Magnet Lab Project8 — 33

S U M M A RY Project 8: • new technology: CRES - Cyclotron Radiation Emission Spectroscopy Next step • measure full tritium spectrum Longer-term future • large scale setup limited by tritium density and molecular excitations 
 → phased antenna array 
 → atomic tritium source Project8 — 34

B A C K U P

A D I A B AT I C I N VA R I A N C E Adiabatic invariance • Φ = B ⋅ A = B π r cycl2 
 ≃ p ⊥ 2 / (q ⋅ B) = const Slowly changing B • p ⊥ → p || 36 Project8 —

M A C - E F I LT E R Magnetic Adiabatic Collimation with Electrostatic Filter Combination of • Adiabatically 
 changing B-field 
 → convert E ⊥ to E || • E-field to 
 filter by energy Resolution • ratio of B s / B A 
 → limited by size 37 Project8 —

D I S E N TA N G L I N G E N E R G Y A N D A N G L E Electron oscillates in trap • axial mode (in harmonic trap) ◆ − 1 ✓ 4 sin θ a ω a ∝ v sin θ + m e cos 2 θ main 
 frequency • sidebands to 
 noise level sidebands cyclotron peak • distance depends 
 on pitch angle θ Project8 — 38

S I D E B A N D O B S E R VAT I O N frequency [MHz] time [s] Project8 — 39

T H R E E D E G R E E S O F F R E E D O M Project8 — 40