Yu. Bunkov E. Collin J. Elbs H. Godfrin

1. Cosmology in the mirror of superfluid 3He The status of new Dark Matter project ULTIMA Yuriy M. Bunkov C R T B T – C N R S, Grenoble, France Yu. Bunkov E. Collin J. Elbs H. Godfrin

2. Superfluid 3He at very low temperatures S=1 L=1 E 3He 2mK D kBT -pF pF • The best condensed matter model system for studding quantum field theories • 18D order parameter 2. The sensitive detector for Dark Matter searching Extremely small heat capacity at 100 mK Quantum vacuum!

3. V(µV) f (Hz) I e i w t V e i w t Lorentz force Induced voltage Self-calibration of 3He bolometer B Width W(T) measures damping by quasiparticles H a 1/W

4. Calibration factor dW = s E Self-calibration of 3He bolometer B Heater Thermo. Heater Records @ ≈ 100 µK, 0 bar, 100 mT During 10h-20h

5. Superfluid 3He bolometry Detector

6. 16% n + 3He = p + 3H + 764 keV 8% Quenching factor 8% Vortex formation (in good agreement with Kibble-Zurek scenario C. Bäuerle, Yu.M. Bunkov, S.N. Fisher, H. Godfrin, G.R. Pickett. ``Laboratory Simulation of Cosmic String Formation in the Early Universe Using Superfluid 3He'‘ Nature, V. 382, p. 332 July, 25, 1996

7. 18 D manifold B Bunkov modification of Kibble-Zurek theory 3He-B Contact of different states and inflation Yu.M. Bunkov, O.D. Timofeevskaya ``"Cosmological" scenario for A-B phase transition in superfluid 3He.'‘ Phys. Rev. Lett, v. 80, p. 4927 (1998).

8. G. Volovik Fine tuning NOT needed!

9. G. Volovik

10. E(mQ)< SE(Q) m In 3He-B In relativistic field theory Q (r) = S - Sz(r) d3x[i(f*dtf - fdtf* )] Q = S+ (r) = S (r) e iwt f (r t) = exp(- imt) f (r) dEd dSz = Dw = gHdd(S,L) E(m) = d3x[ I fI2-mIfI2+ U(IfI)] D Q-ball - Spherically symmetric non-topological soliton with conserved global charge Q Current interest due to Q-balls dark matter model Q ball creates Persistent signal of NMR in 3He Yu.M. Bunkov “Persistent Signal; Coherent NMR state Trapped by Orbital Texture” J. Low Temp. Phys, 138, 753 (2005)

11. Angles of deflection, degree Position, 0.1 mm

12. Angles of deflection, degree Position, 0.1 mm

13. Brain Physics in superfluid 3He Helsinki experiments A phase B phase

14. 3He as a dark matter detector First suggestions G.R.Pickett in Proc. «Second european worshop on neutrinos and dark matters detectors», ed by L.Gonzales-Mestres and D.Perret-Gallix, Frontiers, 1988, p. 377. Yu.Bunkov, S.Fisher, H.Godfrin, A.Guenault, G.Pickett. in Proc. « International Workshop Superconductivity and Particles Detection (Toledo, 1994)», ed. by T.Girard, A.Morales and G.Waysand. World Scientific,p. 21-26. At about 100 mK at 0.1 cm3 remains only 10 keV from the level of absolute zero of temperature. Temperature is the density of quasiparticles, that measured directly by damping of vibrating wire. The deposited energy is intimately associated with the 3He nuclear. There is no isolated nuclear thermal bath, separated from electronic and phononic subsystems!

15. 4. He is the only substance, which remains liquid at Ultra Low Temperatures. The external particles are collide with only single nuclear. There is not effect of "solid body" collision. 5 The nuclear momentum of 3He makes the non-symmetric channel of interaction visible for dark matter.There is one non paired neutron for 3 nuclons! 6. The neutron capture reaction shows the clear signature of neutrons! 7 The absence of free electrons makes 3He relatively insensitive to electromagnetic and gamma radiation background. 8. A the lowest temperatures superfluid 3He is absolutely quantum pure matter. 9. Since the 3He pairs have a nuclear magnetic momentum but no electric charge, the superfluid 3He is transparent to electromagnetic radiation, allowing to employ a very informative NMR methods. NMR can establish magnetically excited quantum state. The latter can be considered rather as metastable state, where instability can be triggered by a small deposit of energy. This variant of particle detector can be tested in future. The small heat capacity, the absolute purity, the liquid state and the relative transparency to gamma radiation background make superfluid 3He a very sensitive nuclear collision detector.

16. Muon histogram: quenching factor≈ 25 % Geant4 simulation Experiment

17. Analysis LPSC, d5 S/B>5 cell B (with source) cell A (without source) Low energy electrons Quenching factor = 26% • • resolution of low energy emission spectrum of 57Co • • Comparison to 14 keV peak with bolometric calibration • Energy deficit of fUV(e-,14keV)≈265%

18. ~ 8 keV 0 100 200 300 Threshold ~ 1 keV Threshold ~ 1 keV

19. Now we are working on Ionization channel

20. Spin dependent interaction 3He N Huge density of non-paired neutrons P P

21. Ultra Low Temperature Instrumentation for Measurements in Astrophysics ULTIMA Collaboration: CRTBT – CNRS, Grenoble, France LPNC – CNRS, Grenoble, France Kyoto University, Japan University Fourie, Grenoble, France Helsinki Technological University, Finland Centre “Cosmion”, Moscow, Russia (2006-2008) Stage 1: New refrigerator for cooling 100g of He to 100 mK Going to underground site. Develop the Ionization channel. Try to use NMR for thermometry. Goal: Try to found axial interacted Dark matter. 3 (2008-??) Stage 2: Detector with 1 kg of 3He for ultimate search of dark matter