# nb-cogwheel_159_103_0_1_-83.in

# approach: selection of the desired coherence (7Q) after the first pulse
#           and (1Q) after the second pulse with cogwheel phase cycling 
#           N = 159, wA = 103, wB = 0, wC = 1, and wRec = -83

# spin-9/2 echo amplitude optimization
# versus the first-pulse duration
# in three-pulse split-t1 7QMAS,
# the second-pulse duration p2 = 4 micro seconds
# the third-pulse duration p3 = 2 micro seconds

spinsys {
  channels 93Nb
  nuclei   93Nb
  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     93000
  variable p2      4 
  variable p3      2 
  variable N       159 
  variable wA      103 
  variable wB      0 
  variable wC      1 
  variable wRec    -83 
}

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 93Nb: "
  puts [resfreq 93Nb $par(proton_frequency)]
}

# SIMP
# NP=17
# SW=4000000
# TYPE=FID
# DATA
# 0 0
# 9.3240744e-09 6.40330988e-09
# 9.39863831e-09 9.82284165e-09
# 1.23277433e-08 1.30685214e-08
# 1.55568299e-07 1.60577729e-08
# 2.75039619e-06 1.87115017e-08
# 2.88025484e-05 2.09557651e-08
# 0.000200319003 2.27243788e-08
# 0.00101787756 2.39622278e-08
# 0.00402646379 2.46303866e-08
# 0.0129595087 2.47110901e-08
# 0.035050097 2.42117988e-08
# 0.0816375703 2.31652386e-08
# 0.166972306 2.16243059e-08
# 0.30473034 1.9653144e-08
# 0.503102221 1.73172783e-08
# 0.76055247 1.46765293e-08
# END