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References - Bogoliubov Laboratory of Theoretical Physics - JINR

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A STUDY OF POLARIZED METASTABLE HELIUM-3 ATOMIC BEAM<br />

PRODUCTION<br />

Yu.A. Plis † and Yu.V. Prok<strong>of</strong>ichev<br />

Joint Institute for Nuclear Research, Dubna, Moscow region, Russia<br />

† E-mail: plis@nusun.jinr.ru<br />

Abstract<br />

The problems <strong>of</strong> metastable 3 He atomic beam formation are considered. The<br />

difference between metastable 3 He and hydrogen or deuterium atoms concerning the<br />

radio-frequency transitions <strong>of</strong> atomic states is essential. The Schroedinger equation<br />

in the uncoupled basis |ψe,ψh > and also in the basis <strong>of</strong> stationary states are<br />

received. The results <strong>of</strong> computer simulations agree with published data. The<br />

possibility to get the positive and negative values <strong>of</strong> helion polarization by using<br />

two types <strong>of</strong> the weak field transitions in the metastable helium-3 atom is shown.<br />

1 Introduction<br />

The spin-dependent part <strong>of</strong> the Hamiltonian for helium-3 atoms in the metastable state<br />

2 3 S1 with electron spin moment one is<br />

ˆH = −μJ � J � B(t) − μh �σh � B(t) − 1<br />

3 ΔW�σh � J, (1)<br />

where �σh are the Pauli spin matrices <strong>of</strong> the helion, � J are the electron spin matrices<br />

(J =1),B(t) is magnetic field strength, ΔW is hyperfine splitting; ΔW =4.4645 × 10 −24<br />

J= �×4.2335×10 10 rad/s, μJ =2μe = −1.85695275×10 −23 J/T= −�×1.76085977×10 11<br />

rad/s T, μh = −1.07455 × 10 −26 J/T= −� × 1.0189 × 10 8 rad/s T.<br />

We consider that a static magnetic field B directed along a z-axis. The wave functions<br />

<strong>of</strong> the hyperfine states Ψ(F, MF ) for this magnetic field and in a high field limit are<br />

Ψ1(1/2, +1/2) = − sin βψ +<br />

h ψ0 J +cosβψ− h ψ+<br />

J<br />

Ψ3(1/2, −1/2) = − sin αψ +<br />

h ψ−<br />

J +cosαψ−<br />

h ψ0 J<br />

sin βψ −<br />

h ψ+<br />

J<br />

⇒ ψ+<br />

h ψ0 J ,Ψ5(3/2, −1/2) = cos αψ +<br />

⇒ ψ−<br />

h ψ+<br />

J ,Ψ2(3/2, +3/2) = ψ +<br />

h ψ+<br />

J ,<br />

⇒ ψ−<br />

h ψ0 J ,Ψ4(3/2, +1/2) = cos βψ +<br />

h ψ0 J +<br />

h ψ−<br />

J<br />

+sin αψ−<br />

h ψ0 J<br />

⇒ ψ+<br />

h ψ−<br />

J ,Ψ6(3/2, −3/2)<br />

= ψ −<br />

h ψ−<br />

J ,wheresinβ = √ A+ , cos β = √ 1 − A+ ;sinα = √ A− , cos α = √ 1 − A− ;<br />

A+ = 1<br />

(1 −<br />

2<br />

x +1/3<br />

�<br />

), A− =<br />

x + x2<br />

1 x − 1/3<br />

(1 − �<br />

);<br />

2<br />

x + x2<br />

1+ 2<br />

3<br />

1 − 2<br />

3<br />

x = B<br />

ΔW<br />

, Bc =<br />

Bc −μJ/J + μI/I =<br />

ΔW<br />

=0.2407 T.<br />

−μJ +2μh<br />

The Breit-Rabi diagram <strong>of</strong> six Zeeman hyperfine components <strong>of</strong> this metastable state<br />

is shown at Fig. 1, where the numbers correspond to those <strong>of</strong> the wave functions.<br />

419

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