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

# approach: filtering the desired coherences (-3Q and +3Q) after the first pulse
#           and (+1Q and -3Q) 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   24*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 3}
  matrix set 2 coherence {1 -3}

  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
# 0.00126024661 1.26116963e-17
# 0.00483799183 7.110587e-18
# 0.0100619674 1.27155336e-17
# 0.0159680152 1.57407111e-17
# 0.0215904077 1.76954808e-17
# 0.0262180886 1.38056656e-17
# 0.02953336 2.2580695e-17
# 0.0316025874 4.23027326e-17
# 0.0327472183 2.66843943e-17
# 0.0333641057 2.78072745e-17
# 0.0337719109 3.27482647e-17
# 0.0341358289 3.34506424e-17
# 0.0344804726 3.46853643e-17
# 0.0347610706 3.09684792e-17
# 0.0349432008 2.87567799e-17
# 0.0350473229 2.8806625e-17
# END