## Central-line intensity optimization with a two-pulse sequence in solid-state MAS NMR using a JDK1.3 applet

## Example 2 of two-pulse MAS simulation

The example, which is complementary to Example 1, also
deals with the **central-line intensity of a spin I = 3/2** in
a powder sample rotating at the magic angle with a **rotor
speed of 10 kHz**.

The strength of the **RF magnetic field is 100 kHz**.

The values of the two quadrupole parameters are **1000 kHz
for the quadrupole coupling constant QCC** and **0 for the
asymmetry parameter eta**.

The simulation associated with the two-pulse sequence is
**A()B(p2)**, where the second-pulse length **p2 increases from 0 to 10
µs by 0.25 µs step**; the first-pulse length **p1 is 6 µs**. There is
no interpulse delay (tau1 = 0, this is an approximation) whereas
experimental tau1 is about 10 µs.

The pulse length to pulse increment ratios are integers.

The number of integration steps for alpha and for beta Euler angles
are **MaxAlpha = 20**, that for gamma Euler angle is **MaxGamma = 10**.

The first pulse excites **the ±3-quantum coherences simultaneously**.

The sign of the central-line intensity **changes several times**
for a range of the second-pulse length p2 that is much shorter
than that of the first-pulse length p1 in Example 1.