# na-spam-antiecho-selective-filtering-p3.in

# approach: filtering the desired coherences (3Q) after the first pulse
#           and (±3Q, ±2Q, ±1Q, and 0Q) after the second pulse

# spin-3/2 antiecho amplitude optimization
# versus the third-pulse duration
# in three-pulse spam 3Q-MAS sequence,
# the first-pulse duration p1 = 4 micro seconds
# the second-pulse duration p2 = 4 micro seconds

spinsys {
  channels 23Na
  nuclei   23Na
  quadrupole 1 1 1e6 1 0 0 0
}

par {
  spin_rate        5000
  variable tsw     0.25
  sw               1.0e6/tsw
  np               17
  crystal_file     rep10
  gamma_angles     10
  proton_frequency 800e6
  start_operator   12*I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     9300
  variable p1      4 
  variable p2      4 
}

proc pulseq {} {
  global par
  maxdt $par(tsw)

  matrix set 1 coherence {3}
  matrix set 2 coherence {9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9}

  acq -y        
  pulse  $par(p1) $par(rf) x
  filter 1
  pulse  $par(p2) $par(rf) x
  filter 2

  for {set i 1} {$i < $par(np)} {incr i} {
    pulse $par(tsw) $par(rf3) x 
    acq -y
  }
}

proc main {} {
  global par

  fsave [fsimpson] $par(name).fid
  puts "Larmor frequency (Hz) of 23Na: "
  puts [resfreq 23Na $par(proton_frequency)]
}

# SIMP
# NP=17
# SW=4000000
# TYPE=FID
# DATA
# 0 0
# -0.90904571 3.61504713e-16
# -0.888278274 3.45407183e-16
# -0.869741348 3.23406774e-16
# -0.853035894 3.1250006e-16
# -0.837768304 2.86359182e-16
# -0.823628471 2.81635836e-16
# -0.81043673 2.74512116e-16
# -0.798151502 2.53751996e-16
# -0.786840491 2.18322878e-16
# -0.776627196 1.90108689e-16
# -0.767628973 1.66161366e-16
# -0.759902571 1.38287019e-16
# -0.753409366 1.26880044e-16
# -0.748006945 1.07543977e-16
# -0.74346775 1.10397405e-16
# -0.739519738 1.08859251e-16
# END