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

Yu. BunkovE. CollinJ. ElbsH. Godfrin

The status of new Dark Matter project ULTIMAYuriy M. Bunkov

C R T B T – C N R S, Grenoble, France

Cosmology in the mirror of superfluid 3He

S=1L=1

Superfluid 3He at very low temperatures

1. The best condensed matter model system for studding quantum field theories

18D order parameter2. The sensitive detector for Dark Matter searching Extremely small heat capacity at 100 K

-pF pF

E

kBT

33HeHe

2mK

Quantum vacuum!Quantum vacuum!

Self-calibration of 3He bolometerB

I e i t

Lorentz force

V e i t-0.05

0

0.05

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)

fréquence (Hz)

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Signal en phase

Signal en quadrature

V(µ

V)

f (Hz)

Induced voltage

Width W(T) measuresdamping by quasiparticles

H 1/W

Self-calibration of 3He bolometer

Records @≈ 100 µK, 0 bar, 100 mT

During 10h-20h

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HeaterHeater Thermo.Thermo.0 500 1000 1500 2000

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tage

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th (

mH

z)

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Calibration factor

W = E

Superfluid 3He bolometry

60 µm hole

Sintered silverCopper box

Vibrating Wires (5 µm and 13 µm)

Detector

16%

n + 3He = p + 3H + 764 keV

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

8% Quenching factor8% Vortex formation (in good agreement with Kibble-Zurek scenario

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).

G. Volovik

Fine tuning NOT needed!

G. Volovik

Q-ball - Spherically symmetric non-topological soliton with conserved global charge Q

Current interest due to Q-balls dark matter model

E(mQ)< E(Q)m

In relativistic field theory

(r t) exp(- it)(r)

Q = d3x[i(dtdt]

E d3x[ I I2 II2 U(II)]

Q (r) = S - Sz(r)

dEddSz

= = Hdd(S,L)

S+ (r) = S (r) e it

In 3He-B

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)

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Brain Physics in superfluid 3He

A phase

B phase

Helsinki experiments

At about 100 At about 100 K at 0.1 cm3 remains only 10 keV K at 0.1 cm3 remains only 10 keV from the level of absolute zero of temperature. from the level of absolute zero of temperature.

Temperature is the density of quasiparticles, that Temperature is the density of quasiparticles, that measured directly by damping of vibrating wire.measured directly by damping of vibrating wire.

The deposited energy is intimately associated The deposited energy is intimately associated with the 3He nuclear. with the 3He nuclear. There is no isolated nuclear thermal bath, There is no isolated nuclear thermal bath, separated from electronic and phononic separated from electronic and phononic subsystems!subsystems!

1011

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ber

of q

uasi

part

icle

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10

cmK

keV )

kT - ( exp

T

103

3He as a dark matter detector

First suggestionsG.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.

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.

Experiment

Geant4 simulation

Muon histogram:

quenching factor ≈ 25 %

cell A (without source)cell B (with source)S/B>5

Analysis LPSC, d5

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)≈265%

0.26

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lin

e w

idth

(H

z)

time (s)

~ 8 keV

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Threshold ~ 1 keV

Threshold ~ 1 keV

Spin dependent interactionSpin dependent interaction

PPN Huge density of non-paired neutrons3He

UUltra LLow TTemperature IInstrumentation for MMeasurements in

AAstrophysicsULTIMAULTIMA

(2006-2008)Stage 1: New refrigerator for cooling 100g of He to 100 K

Going to underground site. Develop the Ionization channel. Try to use NMR for thermometry.

Goal: Try to found axial interacted Dark matter.

3

Stage 2: Detector with 1 kg of 3He for ultimate search of dark matter(2008-??)

Collaboration: CRTBT – CNRS, Grenoble, FranceLPNC – CNRS, Grenoble, FranceKyoto University, JapanUniversity Fourie, Grenoble, France Helsinki Technological University, FinlandCentre “Cosmion”, Moscow, Russia