Presentation on theme: "I want thank Aldo Covello for the 11 Spring Seminars on Nuclear Physics in nice areas of the Sorrento Peninsula and the Islands. I was participating in."— Presentation transcript:
I want thank Aldo Covello for the 11 Spring Seminars on Nuclear Physics in nice areas of the Sorrento Peninsula and the Islands. I was participating in 7 of them. At places like: Sorrento, Ischia, Capri, Amalfi, Ravello, Paestum Thanks go also to Angela Gargano and coorganizers for the organisation of the 11th. Meeting.
Search for the Cosmic Neutrino Background Amand Faessler, Ischia 15. May 2014 With thanks to: Rastislav Hodak, Sergey Kovalenko, Fedor Simkovic; Publication: arXiv: 1304.5632 [nucl-th] 11. Dec. 2013.
1)Cosmic Microwave Background Radiation 2)Cosmic Neutrino Background 3)Cosmic Gravitational Wave Background 1) Decoupling of the photons from matter about 380 000 years after the Big Bang, when the electrons are captured by the protons and He4 nuclei and the universe gets neutral. Photons move freely.
Planck Satellite Temperature Fluctuations Comic Microwave Background (Release March 21. 2013)
Fingerprint of the Gravitational Waves of the Inflationary Expansion of the Big Bang in the Cosmic Background Radiation. On 18. March 2014 the BICEP2 Collaboration published in the arXiv: 1403.3985v2 [astro-ph.CO] Gravitational Waves are Quadrupole Oscillations of Space not in Space.
BICEP2 Detector at the South-Pole
2) Estimate of Neutrino Decoupling Universe Expansion rate: H=(da/dt)/a Interaction rate: n e-e+ Stefan- Boltzmann
(Energy=Mass)-Density of the Universe log a(t)~1/T Matter dominated: ~ 1/a 3 ~ T 3 Dark Energy 1/Temp 1 MeV ~1sec dec. 1 eV 5x10 4 y today 3000 K 380 000 y dec. 8x10 9 y 2.7255 K 1.95 K
How can one detect the Cosmic Neutrino Background? Electron-Neutrino capture on Tritium.
3. Search for Cosmic Neutrino Background C B by Beta decay: Tritium Kurie-Plot of Beta and induced Beta Decay: (CB ) + 3 H(1/2 + ) 3 He (1/2 + ) + e - Electron Energy 2xNeutrino Masses Emitted electron Q = 18.562 keV Infinite good resolution Resolution Mainz: 4 eV m < 2.3 eV Resolution KATRIN: 0.93 eV m < 0.2 eV 90% C. L. Fit parameters: m 2 and Q value meV Additional fit: only intensity of C B
Tritium Beta Decay: 3 H 3 He+e - + c e
Neutrino Capture: (relic) + 3 H 3 He + e - 20 g(eff) of Tritium 2x10 18 T 2 -Molecules: N capture(KATRIN) = 1.7x10 -6 n e / [year -1 ] Every 590 000 years a count! for = 56 cm -3
Problem: 56 e-Neutrinos cm -3 too small Gravitational Clustering of Neutrinos estimated by Y. Wong, P. Vogel et al.: n e (Galaxy) = 10 6 * = 56 000 000 cm -3 1.7 counts per year Increase th source strength: 20 micrograms 2 milligrams 170 counts per year every second day a count Speakers of KATRIN: Guido Drexlin and Christian Weinheimer
20 microgram 2 milligram Tritium Such an Increase of the Tritium Source Intensity is with a KATRIN Type Spectrometer is difficult, if not impossible!
Three important Requirements: 1)The Tritium Decay Electrons are not allowed to scatter with the Tritium Gas. 2) The Magnetic Flux must be conserved in the whole Detection System. 3) The Energy resolution must be of the order of 1 eV.
Source 1)The decay electrons should not scatter by the Tritium gas. Beam Column length d Base 1 cm 2 Tritium Gas Number of Tritium-Atoms in Column d = Column-Density Magnetic Field 3.6 Tesla Optimal Column Density slightly below *d free /2 Troitsk: 30%; Mainz: 40%; KATRIN: 90% Only 36% have not scattered
2) Conservation of Magnetic Flux If one cant increase the intensity per area, increase the area by factor 100 from 53 cm 2 to 5000 cm 2. Magnetic Flux: (A i =5000 cm 2 ) x (B i =3.6 Tesla) = 18 000 Tesla cm 2 = A f x (3 Gauss); A f = 6 000 m 2 diameter = 97 meters
3) Energy resolution of E~ 1 eV Energy resolution: E f (perpend.) = E fp = E
Angular Momentum of the Spiraling Electrons must be conserved
20 microgram 2 milligram Tritium Such an Increase of the Tritium Source Intensity with a KATRIN Type Spectrometer is difficult, if not impossible.
Summary 1 The Cosmic Microwave Background allows to study the Universe 380 000 years after the BB. The Cosmic Neutrino Background 1 sec after the Big Bang (BB). The Cosmic Background of Gravitational Waves 10 -31 Seconds in the Big Bang
2xNeutrino Masses Emitted electron Kurie-Plot Electron Energy Summary 2: Cosmic Neutrino Background 1.Average Density: n e = 56 [ Electron-Neutrinos/cm -3 ] Katrin: 1 Count in 590 000 Years Gravitational Clustering of Neutrinos n / < 10 6 and 20 micrograms Tritium 1.7 counts per year. ( 2 milligram 3 H 170 counts per year. Impossible ?) 2. Measure only an upper limit of n THE END