The name is absent

Chapter 3

magnetization in longitudinal direction and transverse plane at time t. 7^ι and T₂
are time constants, which are referred as longitude relaxation time and transverse
relaxation time.

T₂ can be measured by CPMG (developed by Carr and Purcell^[3] and refined
by Meiboom and Gill^[4]) measurement. For CPMG measurement, the spin echoes
are produced by the a series of 180^o rf pulses following the preparative 90^o pulse,
as shown in Figure 3.1 ^t5j. As time proceeds, relaxation of the magnetization takes
place and the amplitude of the spin-echo is generated after 180^o re-phasing decay.

In the experiment, decay of echo magnitude in the transverse plane is measured
and the equation for the relaxation is ^[5]:

M(2nτ) ™ 2n τ

m

——----= ∕f exp(--) ; 0≤n≤N ; m< N;

M_xy (O)   ⅛^{j, fv} t₂∕

Figure 3.1 Sequence of CPMG measurement

Here N is number of 180^o rf pulses, M_xy(O) is the amplitude corresponding to

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