KATRIN, an experiment for determination of the -mass: status and outlook DSU2012

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1 KATRIN, an experiment for determination of the -mass: status and outlook DSU2012 Michael Sturm for the KATRIN collaboration Karlsruhe Institute of Technology Motivation of m measurement KATRIN experiment Measurement principle Status KIT University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association

2 Impact of the neutrino mass on cosmology m ν = 0 ev/c 2 m = 0 ev/c 2 m = 1 ev/c 2 WMAP m ν = 0.95 ev/c 2 m ν = 1.9 ev/c 2 m = 7 ev/c 2 m = 4 ev/c 2 Agarwal, Feldman 2010 Simulation of evolution of universe Massive neutrinos smear out large scale structure Even tiny neutrino mass has impact on energy content of the universe Neutrino mass is an important input parameter for cosmology m ν < 2 ev/c 2 (PDG10) 1 ev/c kg

Tritium beta decay E 0 = 18.6 kev T 1/2 = 12.

6 kev) Low background + small systematic

3 Tritium beta decay E 0 = 18.6 kev T 1/2 = 12.3 y observable: Requirements: High tritium activity Strong source (> 1 GBq) High energy resolution (< 1 ev@18.6 kev) Low background + small systematic uncertainties KATRIN experiment: 200 mev sensitivity (90 % C.L) After 3 years data (5y real time)

The KATRIN experiment 70 m adiabatic guiding of electrons on mev level Strong gaseous tritium source > 1 GBq electron transport and tritium retention energy analysis + detection Tritium flow rate

4 The KATRIN experiment 70 m adiabatic guiding of electrons on mev level Strong gaseous tritium source > 1 GBq electron transport and tritium retention energy analysis + detection Tritium flow rate reduction by 14 orders of magnitude 4 T 2 gas flow: 1.8 mbar l/s required: small systematic uncertainties stability of source profile better 0.1 % Energy resolution E/E = 0.92 ev required: Low background rate < 10 mhz avoid trapped particles UHV better mbar T 2 pressure < mbar

5 STS = Source & Transport System CMS WGTS DPS2-F CPS Tritium flow rate reduction by 14 orders of magnitude & electron transportation stability of pressure profile on 0.1% level temperature stability on 0.1% 30 K Processing system tritium loops"

1 10 11 Bq 5 10 19 molecules/s 40 g Tritium / day!

6 STS = Source & Transport System CMS WGTS DPS2-F CPS Requirements to tritium source and loops column density: molecules/cm² activity: injection: Bq molecules/s 40 g Tritium / day! content: ultrapure molecular tritium (> 95%) stability: 0.1% (injection, purity, temperature, P in / P in ) = limit of what technically can be done!

7 KATRIN location Germany (TLK) KIT Karlsruhe Institute of Technology Campus North (Research Center Karlsruhe) Commissioned with tritium 1994 License to handle 40 g tritium Scientific Mission: Tritium fuel cycle of fusion reactors KATRIN experiment

Commissioning (tritium): 1994 About 20 g tritium on site 13 glove box systems

8 Key data of TLK Unique, semi-technical facility Long experience in tritium handling at technical scale and in a closed loop License: 40 g tritium Commissioning (tritium): 1994 About 20 g tritium on site 13 glove box systems (total volume of about 125 m³) on an area of about 1450 m² Currently 57 people on board

9 The Tritium Source

Windowless gaseous tritium source (WGTS) for KATRIN Closed tritium loop 40g tritium / day = 1.5 10 16 Bq /day tritium purity T > 95% Pressure stabilization Δp/p < 0.

10 Windowless gaseous tritium source (WGTS) for KATRIN Closed tritium loop 40g tritium / day = Bq /day tritium purity T > 95% Pressure stabilization Δp/p < 0.1% Laser Raman spectroscopy with 0.1% (1σ) precision WGTS cryostat Superconducting solenoids (3.6T) 10 m long beam 30 K with ΔT < 30 mk 2 phase Ne cooling circuit 30 K Experimental test necessary Demonstrator 10m

effects Nonstop test of LARA > 21 days 0.

11 Status of the WGTS Inner Loop system KATRIN-requirements Pressure fluctuations < 0.02% 5 times better than specified Time [d] Laser Raman system (LARA) Study of systematic effects Nonstop test of LARA > 21 days 0.1% precision (1σ) reached KATRIN requirements fulfilled

12 WGTS demonstrator at KIT 12

13 WGTS demonstrator at KIT Kr Cu beam pipe Tritium Demonstrator on site Test measurements nearly finished 2-phase neon heater s.c. Helium vessel Temperature stability in mk range Improvement by w.r.t. specification 13 Time (hh:mm)

14 Transport Section

15 Transport section Adiabatic guidance of electrons to spectrometers Reduction of tritium flow rate by >10 14 T 2 stainless steel Differential pumping section e - B max = 5.6 T Cryogenic pumping section T = K e - B max = 5.6 T T 2 Tritium flow reduction DPS CPS 10 5 >

Status of DPS2-F: Gas-flow reduction measurement

MPIK-Heidelberg) New protection diode layout based on

17 Status of DPS2-F: Gas-flow reduction measurement (without dipoles & FT-ICR) in agreement with simulation Instrumentation for ion detection and elimination 17 FT-ICR Trap (in collaboration with MPIK-Heidelberg) New protection diode layout based on design for WGTS and CPS Cu-heat sink position of dipoles Diode

18 CPS: Status of assembly CPS Ar RT UHV pump port DN100 77K Cold valve DN K Argon frost pump T = K status: presently being manufactured at ASG delivery to KIT in

19 Energy analysis

Electrostatic Spectrometers: pre-filter fixed retarding potential U 0 = -18.

ionising collisions no info on m(n) precision filter - scanning variable retarding

20 Electrostatic Spectrometers: pre-filter fixed retarding potential U 0 = kv E ~ 100 ev filter out all ß-decay electrons without m( )-info reduce background from ionising collisions no info on m(n) precision filter - scanning variable retarding potential U 0 = kv E ~ 0.93 ev (100% transmission) tandem design: pre-filter & energy analysis

the final 7km: passing Leopoldshafen November 25, 2006:

vessel was manoeuvred on road over 7 km to the final

000 visitors) arrival at Leimersheim ferry & reloading onto

21 the final 7km: passing Leopoldshafen November 25, 2006: after an 8800 km sea-going voayge the main Spectrometer vessel was manoeuvred on road over 7 km to the final destination at the KATRIN experimental halls ( visitors) arrival at Leimersheim ferry & reloading onto SPMT with heavy-duty crane In pictures: photos of the year 2006 SPMT

22 Status of the main spectrometer spectrometer wall U 0 =-18.4kV U 0-100V e - Wire defined electrostatic filter: 248 modules, wires precision requirement 0.2 mm compatible to UHV Michael EPSHEP Sturm 2011, Grenoble DSU2012 Búzíos Sebastian Fischer wire frame module U 0-200V Wire modules installed First test measurements in 2012 m B

23 KATRIN Impressions (Main Spectrometer) Lenght: 24 m Diameter: 10 m Volume: 1240 m³ Surface: 690 m² Weight: 200 t Pressure: mbar Outgassing: mbar 20 C Heating/cooling: from C 3 pump ports: 1700 mm diameter 10 4 l/s with 6 TMPs MAG W 2800 for H * 10 5 l/s with 3000 m of NEG (with baffle) for H

24 The detector system Segmented Si-PIN diode Detection of transmitted beta decay electrons (Hz to khz) Low intrinsic background (< 1 mhz) Commissioning ongoing Detector system at University of Washington before shipping Delivery to KIT, July mm

25 Summary Measurement of m ν with 200 mev/c 2 design sensitivity (90 % C.L.) Commissioning of components ongoing Many central parameters better than specified Many systematic effects understood Start of tritium measurements 1 year after delivery of WGTS

26 Thank you for your attention

Motivation for neutrino mass measurement Cosmology 0νββ decay Mass hierarchy quasi-degenerate

) (PDG08) Improved direct measurement necessary m U 3 i 1 n e, i 0.

28 Motivation for neutrino mass measurement Cosmology 0νββ decay Mass hierarchy quasi-degenerate scenario m ν = 0 ev/c 2 m ν = 1 ev/c 2 m ν = 7 ev/c 2 m ν = 4 ev/c 2 Σm ν < (0.6 2) ev/c 2 (95 % C.L.) (Hannestad) Direct beta decay measurements (Mainz, Troitsk): m ν < 2 ev/c 2 (95 % C.L.) (PDG08) Improved direct measurement necessary m U 3 i 1 n e, i 0.35eV ν m n (Heidelberg-Moscow, IGEX) 2 m i e i i hierarchical scenario Neutrino oscillations: Atmospheric neutrinos: (Δm 32 ) ev 2 /c 4 Solar neutrinos: (Δm 21 ) ev 2 /c 4 m ν 0 (PDG08)

29 KATRIN sensitivity After 3 years data (5y real time): discovery potential m( ) = 0.35 ev/c² (5σ) sensitivity (90% CL) m( ) < 0.2 ev/c² s tot 2 = s stat2 +s systot ev 2 /c 4 s stat = s systot ev 2 /c 4 Δm stat 2 = ev 2 /c 4 Δm sys,tot ev 2 /c

The MAC-E spectrometers Pre spectrometer Spectrometer Detector Magnetic Adiabatic Collimation with Electrostatic Filter (A. Picard et al., Nucl. Instr. Meth.

30 The MAC-E spectrometers Pre spectrometer Spectrometer Detector Magnetic Adiabatic Collimation with Electrostatic Filter (A. Picard et al., Nucl. Instr. Meth. 63 (1992) 345) B min = B max ΔE = E B min / B max = 0.93 ev (E 0 = 18.6 kev) Magnetic moment µ = E t / B = const. Magnetic adiabatic collimation Large solid angle (2π)

Direct Neutrino Mass Measurement with KATRIN. Sanshiro Enomoto (University of Washington) for the KATRIN Collaboration

Direct Neutrino Mass Measurement with KATRIN Sanshiro Enomoto (University of Washington) for the KATRIN Collaboration DBD16, Osaka, Japan, 8 Nov 2016 Neutrino Mass Measurement with Single Beta Decay 2