# al-spam-echo-3Q-selective-12-cycling-p2.in

# approach: 12-phase cycling the first pulse and the receiver

# spin-5/2 echo amplitude optimization
# versus the second-pulse duration
# in three-pulse spam-echo 3Q-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   I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     9300
  variable p1      4 
  variable p3      2 
  variable NA      12
  variable deltapA -3
}

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

  pulse  $par(p1) $par(rf) $par(phA)
  store 10

  reset
  acq $par(phREC)
  for {set i 1} {$i < $par(np)} {incr i} {
    reset
    prop 10
    pulse [expr ($i)*$par(tsw)] $par(rf)  x
    pulse $par(p3)              $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
# -0.0633686745 1.0269563e-15
# -0.335386192 8.04911693e-16
# -0.973308634 -6.66133815e-16
# -1.98239879 -1.77635684e-15
# -3.14151327 -2.88657986e-15
# -4.06404257 -3.10862447e-15
# -4.36920076 -3.33066907e-15
# -3.86582779 -3.55271368e-15
# -2.64926301 -3.99680289e-15
# -1.06945125 -4.21884749e-15
# 0.401518484 -5.77315973e-15
# 1.33520809 -6.88338275e-15
# 1.48174021 -6.21724894e-15
# 0.83624889 -5.77315973e-15
# -0.37374321 -4.4408921e-15
# -1.7717808 -2.44249065e-15
# END