# al-zfilter-amplitude-filtering-p3.in

# approach: filtering the desired coherences (-3Q and +3Q) after the first pulse
#           and (0Q) after the second pulse

# spin-5/2 echo and antiecho amplitude optimization
# versus the third-pulse duration
# in three-pulse z-filtered amplitude-modulated 3Q-MAS sequence,
# the first-pulse duration p1 = 4 micro seconds
# the second-pulse duration p2 = 4 micro seconds

spinsys {
  channels 27Al
  nuclei   27Al
  quadrupole 1 2 3e6 0 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   36*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 {0}

  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 27Al: "
  puts [resfreq 27Al $par(proton_frequency)]
}

# SIMP
# NP=17
# SW=4000000
# TYPE=FID
# DATA
# 0 0
# -1.38277879 0.000645762422
# -4.40208148 0.00260389924
# -9.35287374 0.00579076744
# -14.960624 0.00978496391
# -19.2049901 0.0137644414
# -20.4072812 0.0169987026
# -17.9708067 0.0199159826
# -12.6017732 0.0243159492
# -6.07188684 0.031537341
# -0.524895349 0.0402735713
# 2.52904281 0.0465318841
# 2.9331155 0.0457915224
# 1.76994674 0.0357083716
# 0.541030828 0.0175964833
# 0.264615889 -0.00417083692
# 1.04711595 -0.0241359187
# END