# al-spam-antiecho_-3Q-selective-filtering-p3.in

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

# spin-5/2 antiecho amplitude optimization
# versus the third-pulse duration
# in three-pulse spam -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 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   12*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}
  matrix set 2 coherence {9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9}

  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
# 1.8871062 -2.59996885e-16
# 1.92309819 -3.49427035e-16
# 1.96698482 -4.15699485e-16
# 2.01833312 -4.97638902e-16
# 2.07646008 -5.35672168e-16
# 2.14045668 -5.50611147e-16
# 2.20925184 -5.87132904e-16
# 2.28168334 -6.4023296e-16
# 2.35654726 -6.93223107e-16
# 2.43261523 -7.41925704e-16
# 2.50862941 -7.92739357e-16
# 2.58329755 -8.53987901e-16
# 2.65530964 -9.89258309e-16
# 2.72338582 -1.05971448e-15
# 2.78634898 -1.09600547e-15
# 2.84320419 -1.11646457e-15
# END