# na-shifted-echo-amplitude-selective-filtering-p1.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 first-pulse duration
# in three-pulse shifted-echo amplitude-modulated 3Q-MAS sequence,
# the second-pulse duration p2 = 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   24*I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     9300
  variable p2      4 
  variable p3      2 
}

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

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

  acq -y        
  for {set i 1} {$i < $par(np)} {incr i} {
    pulse $par(tsw) $par(rf) x
    store 2
    filter 1
    pulse $par(p2)  $par(rf) x
    filter 2
    pulse $par(p3) $par(rf3) x
    acq -y
    reset
    prop 2
  }
}

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
# 6.8899869e-07 -3.02732944e-19
# 2.12223522e-05 2.4208332e-19
# 0.000151178414 -1.52773181e-19
# 0.000581766162 -3.13927842e-19
# 0.00157611006 -1.64311172e-19
# 0.00338016096 -1.11658317e-18
# 0.00610749622 -5.37531001e-18
# 0.00965282028 -5.34002971e-18
# 0.0136854856 -6.61742931e-18
# 0.0177409185 -5.58516388e-18
# 0.0213780437 -1.19267366e-17
# 0.0243322783 -1.32864804e-17
# 0.0265915289 -1.76681206e-17
# 0.0283614981 -1.96659073e-17
# 0.029944974 -2.40457249e-17
# 0.0316025874 8.36682266e-18
# END