Status of the KATRIN Experiment and commissioning of the spectrometer and detector section Thomas Thümmler for the KATRIN collaboration DESY-Physikseminar, June 2013, Hamburg & Zeuthen KIT Center Elementary Particle and Astroparticle Physics (KCETA) Institute for Nuclear Physics (IKP) KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association
Goal of KATRIN model-independent neutrino mass determination ! ! " precise spectroscopy of Tritium ! -decay ! ! " unprecedented sensitivity of " ! " ! ! ! ! 200 meV/c 2 (90% C.L.) ! Introduction and KATRIN setup ! ! " Spectrometer-, Detector-Section ! ! " Status and Commissioning runs ! ! " Summary and Outlook ! ! " 2 T. Thümmler - Status and commissioning of KATRIN
Motivation: Neutrinos in Astroparticle Physics cosmology: role of ! ! ´s as hot (warm?) dark matter? particle physics: origin and hierarchy of the ! ! -mass? cosmology particle physics fermions bosons neutrinos Millennium Simulation massless bosons 3 T. Thümmler - Status and commissioning of KATRIN
Neutrino Mass: Status and Perspectives Experiments on Neutrino Oscillations: Clear evidence for neutrino flavour oscillations: ! ! " ! ( ! m 32 ) 2 � 2.4 # 10 -3 eV 2 /c 4 Atmospheric neutrinos: ! ! ! " ! ( ! m 21 ) 2 � 7.6 # 10 -5 eV 2 /c 4 ! Solar neutrinos: ! ! " ! " Well established fact: m " �� 0 ! ! Input from Cosmology: measures # m i and HDM $ " ! ! " very sensitive, but model dependent! ! ! " Planck: # m i < 0.98 eV " ! " (Planck 2013 results. XVI. Cosm. param.) ! potential: # m i = 20-50 meV " ! " (Planck, LSST, weak lensing) ! 4 T. Thümmler - Status and commissioning of KATRIN
Neutrino Mass: Status and Perspectives neutrino masses in lab. experiments 5 T. Thümmler - Status and commissioning of KATRIN
Neutrino Mass: Status and Perspectives neutrino masses in lab. experiments search for 0 ! ßß eff. Majorana mass m ßß ! model-dependent (CP-phases) ! ! effective Majorana mass: ! � � ! � � � U 2 ei · m ν i m ββ = � � ! � � � � i !" probe " as Majorana particle: ? ! ν = ¯ ν ! status: m ßß < 0.35 eV, evidence? ! !" potential: m ßß = 20-50 meV ! !" GERDA, EXO, SNO+, MAJORANA, " Cuore, KamLAND-Zen, ... ! 6 T. Thümmler - Status and commissioning of KATRIN
Neutrino Mass: Status and Perspectives neutrino masses in lab. experiments search for 0 ! ßß kinematics of ß-decay eff. Majorana mass m ßß absolute ! ! e -mass: m ! ! model-independent ! ! model-dependent (CP-phases) ! ! squared neutrino mass: ! ! ! effective Majorana mass: ! | U ei | 2 · m 2 � m 2 ν e = ! � � ! ν i � � � U 2 ! ei · m ν i m ββ = � � i ! � � ! direct, from kinematics ! � � i !" probe " as Majorana particle: ? ! ν = ¯ ν ! status: m ! < 2.3 eV ! ! status: m ßß < 0.35 eV, evidence? ! !" potential: m ! = 200 meV ! !" potential: m ßß = 20-50 meV ! !" KATRIN, MARE, " !" GERDA, EXO, SNO+, MAJORANA, " Project 8, ECHO " Cuore, KamLAND-Zen, ... ! ! 7 T. Thümmler - Status and commissioning of KATRIN
ß-decay – Fermi theory & ! -mass ß-decay kinematics close to endpoint E 0 : model independent measurement of m( ! e ), based solely on kinematic parameters & energy conservation d " ( E 0 $ E ) 2 $ m i 2 # F ( E , Z ) # % ( E 0 $ E $ m i ) i d E = C # p # ( E + m e ) # ( E 0 $ E ) # observable m 2 ( " e ): 3 2 # $ 2 m ( " e ) = U ei m i effective electron- " -mass i = 1 8 T. Thümmler - Status and commissioning of KATRIN
ß-decay – Fermi theory & ! -mass ß-decay kinematics close to endpoint E 0 : model independent measurement of m( ! e ), based solely on kinematic parameters & energy conservation d " ( E 0 $ E ) 2 $ m i 2 # F ( E , Z ) # % ( E 0 $ E $ m i ) i d E = C # p # ( E + m e ) # ( E 0 $ E ) # observable m 2 ( " e ): 3 2 # $ 2 m ( " e ) = U ei m i effective electron- " -mass i = 1 � 3 � ∆ E E 0 !" small modifications by final states, radiative & recoil corrections 9 T. Thümmler - Status and commissioning of KATRIN
ß-decay – Fermi theory & ! -mass ß-decay kinematics close to endpoint E 0 : model independent measurement of m( ! e ), based solely on kinematic parameters & energy conservation d " ( E 0 $ E ) 2 $ m i 2 # F ( E , Z ) # % ( E 0 $ E $ m i ) i d E = C # p # ( E + m e ) # ( E 0 $ E ) # observable m 2 ( " e ): 3 2 # $ 2 m ( " e ) = U ei m i effective electron- " -mass i = 1 � 3 � ∆ E key requirements: E 0 !" low endpoint ! source !" high count rate !" high energy resolution !" extremely low background !" small modifications by final states, radiative & recoil corrections 10 T. Thümmler - Status and commissioning of KATRIN
The MAC-E filter Magnetic Adiabatic Collimation with Electrostatic Filter A. Picard et al., NIM B 63 (1992) � Design Facts: B max = 6 T ! B min = 0.3 mT ! B min / B max = 5∙10 -5 μ = E � / B = const. U 0 = 18.6 kV E = 18.6 keV E = E � + E || adiabatic transport: E � ! E || due to μ = const. !" collimation: !" energy analysis: only electrons with E || > eU 0 (retarding potential) can pass analysing plane � high-pass filter with a sharp transmission function, no tails! !" energy resolution: ! ! E = E ∙ B min / B max = 0.93 eV 11 T. Thümmler - Status and commissioning of KATRIN
The KATRIN Setup - Overview Tritium source Transport section Pre spectrometer Spectrometer Detector " E = 0.93 eV E > 18.3 keV e - 1 e - /s v e e - e - 3 H e - e - 10 3 e - /s e - " decay e - 0 11 s 10 11 e - /s / 1 3 He 3 H E = 18600 eV 3 He � 70 m ! 12 T. Thümmler - Status and commissioning of KATRIN
magnetic field & electrostatic potential tritium source B max spectrometer 1 B-field [T] 10 -1 10 -2 B min potential [kV] -20 -10 0 -40 -30 -20 -10 0 +10 distance from analysing plane [m] 13 T. Thümmler - Status and commissioning of KATRIN
The KATRIN Setup tritium-bearing components electrostatic spectrometers & detector 10 11 electrons/s tritium source <10 -2 cps total background " 10 -3 stability of tritium source column density " " d " retention factor for molecular tritium R = 10 14 " effective removal of ions " " fully adiabatic (meV scale) transport of electrons over > 50 m " " avoid particle storage in Penning-like traps " " avoid contermination by Rn in the volume 14 T. Thümmler - Status and commissioning of KATRIN
Windowless Gaseous Tritium Source WGTS WGTS 16 m Design parameter luminosity ! 1.7 # 10 11 Bq ! Tritium Laboratory Karlsruhe ! - a unique research facility in Europe ! injection rate ! 5 # 10 19 T 2 /s � 40 g/day � 10 kg/y ! Tritium purity ! > 95% ! ±0.1 % ! temperature ! T = 27 K ± 30 mK ! ±0.1 % ! pressure ! p inj � 10 -3 mbar ! ±0.1 % ! magnetic guiding ! B = 3.6 T ! CAPER facility 15 T. Thümmler - Status and commissioning of KATRIN
Windowless Gaseous Tritium Source WGTS ISS glove box KATRIN tritium loop system CMS-R DPS1-R WGTS DPS1-F DPS2-F 5% 95% 95% 5% batch inner loop mode, 60 days control system (<1 Ci) T 2 injection T 2 retention- 1% 1% system T 2 preparation isotope separation permeator Up and running extremely stable! ! designed for a stability at 10 -3 level ! achieved: 2 # 10 -4 over 4 months 16 T. Thümmler - Status and commissioning of KATRIN
Windowless Gaseous Tritium Source WGTS S. Grohmann et al., Cryogenics, Volume 51, Issue 8, August 2011 WGTS Demonstrator: KATRIN requirement: ! on-site and cold tested T = 27 K with " T < 30 mK in 2010 ! " T max = ± 3 mK Cu Tritium Kr Temperature [K] ! beam tube conzept: 2-Phasen Neon (sied. Flüssigkeit) Helium 2 phase s.c heater vessel Neon . s 17 T. Thümmler - Status and commissioning of KATRIN
Transport and Pumping Sections O. Kazachenko et al., NIM A 587 (2008) 136 F. Eichelhardt et al, Fusion Science and Technology 54 (2008) 615 DPS2-F CPS cryo-sorption T 2 stainless steel ß´s ß´s Argon Frost Pump T = 3 – 4.5 K ! active pumping, 4 TMPs !" Tritium retention 10 5 ! pumping by cryo-sorption ! magnetic field: 5.6 T !" Tritium retention >10 7 ! under construction, to be installed 2014 ! magnetic field: 5.6 T ! delivery Spring 2014 18 T. Thümmler - Status and commissioning of KATRIN
Electrostatic Spectrometers pre-filter option precision filter - scanning fixed retarding potential variable retarding potential U 0 = - 18.3 kV U 0 = - 18.4 … -18.6 kV # E ~ 100 eV # # E ~ 0.93 eV (100% transmission) # no info - " filter out all ß-decay on m( ! ) electrons without m( ! ! )-info - reduce background from ionising collisions tandem design: pre-filter & energy analysis 10 11 electrons/s ! 10 -2 electrons/s 19 T. Thümmler - Status and commissioning of KATRIN
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