# na-cogwheel_23_0_3_4_14.in

# approach: selection of the desired coherence (3Q) after the first pulse
#           and (1Q) after the second pulse with cogwheel phase cycling 
#           N = 23, wA = 0, wB = 3, wC = 4, and wRec = 14
#           Cog23(0, 3, 4, 14)

# spin-3/2 anti echo amplitude optimization
# versus the first-pulse duration
# in three-pulse split-t1 3QMAS,
# the second-pulse duration p2 = 4 micro seconds
# the third-pulse duration p3 = 2 micro seconds

spinsys {
  channels 23Na
  nuclei   23Na
  quadrupole 1 1 1e6 1 0 0 0
}

par {
  spin_rate        5000
  variable tsw     0.25
  sw               1.0e6/tsw
  np               17
  crystal_file     rep100
  gamma_angles     10
  proton_frequency 800e6
  start_operator   I1z
  detect_operator  I1c
  verbose          1101
  variable rf      90000
  variable rf3     93000
  variable p2      4 
  variable p3      2 
  variable N       23 
  variable wA      0 
  variable wB      3 
  variable wC      4 
  variable wRec    14 
}

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

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

proc main {} {
  global par

  for {set j 0} {$j < $par(N)} {incr j} {

    set par(phA)   [expr $j*$par(wA)*360./$par(N)]
    set par(phB)   [expr $j*$par(wB)*360./$par(N)]
    set par(phC)   [expr $j*$par(wC)*360./$par(N)]
    set par(phREC) [expr $j*$par(wRec)*360./$par(N)]

    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 23Na: "
  puts [resfreq 23Na $par(proton_frequency)]
}

# SIMP
# NP=17
# SW=4000000
# TYPE=FID
# DATA
# 0 0
# -2.05584676e-05 -1.80658322e-10
# -0.000619528229 -2.29705699e-10
# -0.00425033373 -2.76604351e-10
# -0.0155614268 -3.18054916e-10
# -0.0398291135 -3.5022607e-10
# -0.080692798 -3.70096287e-10
# -0.138941008 -3.76458753e-10
# -0.213223133 -3.70042885e-10
# -0.301964834 -3.5281833e-10
# -0.404752632 -3.27064709e-10
# -0.521872148 -2.94779201e-10
# -0.652226709 -2.57617927e-10
# -0.791301451 -2.17219742e-10
# -0.931003981 -1.75485515e-10
# -1.06193022 -1.34575684e-10
# -1.17683433 -9.66428465e-11
# END