# na-shifted-echo-amplitude-filtering-p3.in

# approach: filtering the desired coherences (-3Q and +3Q) after the first pulse
#           and (+1Q) after the second pulse

# spin-3/2 echo and antiecho amplitude optimization
# versus the third-pulse duration
# in three-pulse shifted-echo amplitude-modulated 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     rep100
  gamma_angles     10
  proton_frequency 800e6
  start_operator   48*I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     93000
  variable p1      4 
  variable p2      4 
}

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

  matrix set 1 coherence {-3 3}
  matrix set 2 coherence {1}

  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
# 0.0605879996 1.07972142e-17
# 0.237746387 -3.73261037e-17
# 0.490037728 -1.23830595e-16
# 0.739335004 -1.38570718e-16
# 0.890824698 -1.67509599e-16
# 0.857489384 -1.97032469e-16
# 0.582668738 -1.30840582e-16
# 0.0558592671 -2.56491429e-17
# -0.681035074 1.27547713e-16
# -1.53809629 2.85640754e-16
# -2.39213322 4.50043452e-16
# -3.10983537 5.40765319e-16
# -3.57528247 5.58707579e-16
# -3.71572367 4.91250166e-16
# -3.51879584 3.97864416e-16
# -3.03589484 2.92792915e-16
# END