# al-spam-echo_-5Q-selective-20-cycling-p3.in

# approach: 20-phase cycling the first pulse and the receiver

# spin-5/2 antiecho amplitude optimization
# versus the third-pulse duration
# in three-pulse spam-echo 5Q-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   I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     9300
  variable p1      4 
  variable p2      4 
  variable NA      20
  variable deltapA 5
}

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

  acq $par(phREC)
  pulse  $par(p1) $par(rf) $par(phA)
  pulse  $par(p2) $par(rf) x

  for {set i 1} {$i < $par(np)} {incr i} {
    pulse $par(tsw) $par(rf3) -x
    acq                 [expr $par(phREC) - 90]
  }
}

proc main {} {
  global par

  for {set jA 0} {$jA < $par(NA)} {incr jA} {
    set par(phA)   [expr $jA*360./$par(NA)]
    set par(phREC) [expr $par(deltapA)*$par(phA)]

    set g [fsimpson]
    if [info exists f] {
      fadd $f $g
      funload $g
    } else {
      set f $g
    }
  }

  fsave $f $par(name).fid
  funload $f
  puts "Larmor frequency (Hz) of 27Al: "
  puts [resfreq 27Al $par(proton_frequency)]
}

# SIMP
# NP=17
# SW=4000000
# TYPE=FID
# DATA
# 0 0
# 0.979721664 1.55431223e-015
# 1.01806 8.8817842e-016
# 1.06388759 6.66133815e-016
# 1.11727196 0
# 1.17793171 -2.22044605e-016
# 1.2451446 -8.8817842e-016
# 1.31775337 -1.77635684e-015
# 1.39426804 -1.55431223e-015
# 1.47303414 -1.77635684e-015
# 1.55241843 -2.88657986e-015
# 1.63096307 -2.22044605e-015
# 1.70747489 -3.10862447e-015
# 1.78104127 -3.55271368e-015
# 1.85098957 -3.77475828e-015
# 1.9168224 -4.4408921e-015
# 1.97816311 -3.55271368e-015
# END