# na-shifted-echo-amplitude-filtering-p2.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 second-pulse duration
# in three-pulse shifted-echo amplitude-modulated 3Q-MAS sequence,
# the first-pulse duration p1 = 4 micro seconds
# the third-pulse duration p3 = 2 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 p3      2 
}

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

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

  pulse  $par(p1) $par(rf) x
  store 10

  reset
  acq -y        
  for {set i 1} {$i < $par(np)} {incr i} {
    reset
    prop 10
    filter 1
    pulse [expr ($i)*$par(tsw)] $par(rf) x 
    filter 2
    pulse $par(p3) $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
# -0.250325564 5.84682114e-17
# -0.869687832 1.78941782e-16
# -1.59285066 3.30145163e-16
# -2.15155497 4.13789616e-16
# -2.3669218 3.23639258e-16
# -2.19207938 3.64093506e-16
# -1.69786297 2.5134963e-16
# -1.02232874 1.83345952e-16
# -0.315559878 -6.70682249e-18
# 0.297570191 5.98193078e-17
# 0.732185825 -1.28668222e-16
# 0.94487017 -2.23989831e-16
# 0.93242732 -1.9812795e-16
# 0.73084361 -1.43635966e-16
# 0.409573634 -7.1796366e-17
# 0.0558592671 -4.78939618e-19
# END