# al-spam-echo-3Q-selective-12-cycling-p1.in

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

# spin-5/2 echo amplitude optimization
# versus the first-pulse duration
# in three-pulse spam-echo 3Q-MAS sequence,
# the second-pulse duration p2 = 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 p2      4 
  variable p3      2
  variable NA      12
  variable deltapA -3
}

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

  acq $par(phREC)
  for {set i 1} {$i < $par(np)} {incr i} {
    pulse $par(tsw) $par(rf)  $par(phA) 
    store 2
    pulse $par(p2)  $par(rf)  x
    pulse $par(p3)  $par(rf3) x
    acq                 [expr $par(phREC) - 90]
    reset
    prop 2
  }
}

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
# -5.80617938e-07 1.66533454e-16
# -0.000178750904 -1.94289029e-16
# -0.00239501066 -6.66133815e-16
# -0.0132690557 -8.8817842e-16
# -0.045926636 -1.88737914e-15
# -0.117539787 -1.11022302e-16
# -0.242810123 4.4408921e-16
# -0.426754533 -1.99840144e-15
# -0.660913172 -1.99840144e-15
# -0.924878509 -2.22044605e-15
# -1.19172089 8.8817842e-16
# -1.43403483 -2.22044605e-16
# -1.6280614 -1.11022302e-15
# -1.75557181 -3.33066907e-15
# -1.80483022 -3.77475828e-15
# -1.7717808 -4.88498131e-15
# END