# al-spam-echo_-5Q-selective-filtering-p2.in

# approach: filtering the desired coherences (-5Q) after the first pulse
#           and (±5Q, ±4Q, ±3Q, ±2Q, ±1Q, and 0Q) after the second pulse

# spin-5/2 echo amplitude optimization
# versus the second-pulse duration
# in three-pulse spam -5Q-MAS sequence,
# the first-pulse duration p1 = 4 micro seconds
# the third-pulse duration p3 = 2 micro seconds

spinsys {
  channels 27Al
  nuclei   27Al
  quadrupole 1 1 1e6 1 0 0 0
}

par {
  spin_rate        5000
  variable tsw     0.25
  sw               1.0e6/tsw
  np               17
  crystal_file     rep10
  gamma_angles     10
  proton_frequency 800e6
  start_operator   20*I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     9300
  variable p1      4 
  variable p3      2 
}

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

  matrix set 1 coherence {-5}
  matrix set 2 coherence {9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9}

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

# SIMP
# NP=17
# SW=4000000
# TYPE=FID
# DATA
# 0 0
# 0.00200696357 5.0037468e-019
# 0.0261197166 3.66189315e-018
# 0.161117563 2.38210495e-017
# 0.516334926 8.55380088e-018
# 1.12654771 -5.41581672e-017
# 1.90196929 -2.47057989e-016
# 2.6600512 -3.76375503e-016
# 3.21562663 -3.86825592e-016
# 3.46755336 -3.71025466e-016
# 3.42859143 -1.13969283e-016
# 3.18974845 -4.70628185e-016
# 2.85437521 -7.96459776e-016
# 2.48952446 -8.49521124e-016
# 2.11917987 -8.07177955e-016
# 1.74912421 -5.39933048e-016
# 1.39426804 -1.03332017e-016
# END