# 1 "/u/exp/stan/nmr/lists/pp/cpmg-il2-hsqc-rk-fb+3919.sm.cpj"
;cpmg-hsqc-rk-fb+3919.sm.cpj
;
;CPMG sequence from D. F. Hansen, P. Vallrupalli, L. E. Kay, J. Phys. Chem. B, 2008, 112, 5898-5904
;Modified from hsqc-rk-fb+3919.cpj for 800 cryoprobe
;
;gradient and sensitivity enhanced HSQC with water flip-back pulses + 3-9-19 pulse
;for water suppression
;
;SM - Aug/31/2009
;SM - edited Oct/02/2009 include suggestions by Alex & Flemming Hansen, Kay group (separate first 15N-180 pulse, equalize CPMG halfs).
;Edited by JW and JRS (interleaving)
;SM - Feb12 2010 - 15N compensation pulses post Acq. to maintain constant RF duty cycle from N=0 to N_max
;
; ---- old comments -----------------------------------
;2D HSQC gradient and sensitivity enhanced
;with water flip-back pulses
;**** this set-up for z-axis gradients only ****
;**** for 3-axis gradients see hsqc-rk-fb-3919-3ax.cpj
;Echo/Antiecho gradient selection in F1
;waltz-16 decoupling during acquisition
;A.G. Palmer III, J. Cavanagh, P.E. Wright & M. Rance, J. Magn.
;   Reson. 93, 151-170 (1991)
;L.E. Kay, P. Keifer & T. Saarinen, J. Am. Chem. Soc. 114,
;   10663-5 (1992)
;J. Schleucher, M. Schwendinger, M. Sattler, P. Schmidt, O. Schedletzky,
;   S.J. Glaser, O.W. Sorensen & C. Griesinger, J. Biomol. NMR 4,
;   301-306 (1994)
; 
; gradient ratio: 0.1013 for 15N 
;----------- end old comments ---------------------
;
;----------Calculations to set CPMG pulse delays, Spin Lock fields, etc -------
;
;	Total relaxation time = T-relax
;	Number of pulses (T-relax/2 interval) = N
;	Delay between CPMG pulses = d = (2*tau_cpmg+2*pw90N) = (T-relax/2N)
;	cpmg_freq = 1/(2*d) = 1/(2*(2*tau_cpmg+2*pw90N)) = (N/T-relax)
;	freq_SL (Spin Lock field) = (wSL/2Pi) = 2*k*cpmg_freq , where k=integer
;	=> k = (freq_SL)/(2*cpmg_freq) = 15000/(2*N/T-relax) = (15000*T-relax)/(2*N)
;	Set k to integer lower than the value above.
;	Then set pw90H(SpinLock) = 1/(4*freq_SL) 
;	=> pw90H(Spinlock) = 1/(4*2*k*cpmg_freq)and set power level accordingly.
;	freq_SL (Hz) = wSL/(2*Pi), where wSL is SpinLock field in radians
;	Delay "Chi" = (1/wSL)-(4/Pi)*pw90H = 1/(2*Pi)*((1/freq_SL)-8*pw90H)
;-----------------------------------------------------------------------------------
;

# 1 "/u/exp/stan/nmr/lists/pp/Avance.incl" 1
;Avance.incl
;
;avance-version (03/02/17)


















































































































;$Id: Avance1.incl,v 1.7.2.3 2003/02/25 14:48:47 ber Exp $
# 48 "/u/exp/stan/nmr/lists/pp/cpmg-il2-hsqc-rk-fb+3919.sm.cpj" 2

# 1 "/u/exp/stan/nmr/lists/pp/Grad.incl" 1
;Grad.incl  -  include file for Gradient Spectroscopy
;
;avance-version (02/05/31)



















define list<gradient> EA=<EA>



;$Id: Grad1.incl,v 1.7 2002/06/12 09:04:22 ber Exp $
# 49 "/u/exp/stan/nmr/lists/pp/cpmg-il2-hsqc-rk-fb+3919.sm.cpj" 2

# 1 "/u/exp/stan/nmr/lists/pp/Delay.incl" 1
;Delay.incl  -  include file for commonly used delays
;
;version 00/02/07


;general delays

define delay DELTA
define delay DELTA1
define delay DELTA2
define delay DELTA3
define delay DELTA4
define delay DELTA5
define delay DELTA6
define delay DELTA7
define delay DELTA8

define delay TAU
define delay TAU1
define delay TAU2
define delay TAU3
define delay TAU4
define delay TAU5


;delays for centering pulses

define delay CEN_HN1
define delay CEN_HN2
define delay CEN_HN3
define delay CEN_HC1
define delay CEN_HC2
define delay CEN_HC3
define delay CEN_HC4
define delay CEN_HP1
define delay CEN_HP2
define delay CEN_CN1
define delay CEN_CN2
define delay CEN_CN3
define delay CEN_CN4
define delay CEN_CP1
define delay CEN_CP2


;loop counters

define loopcounter COUNTER
define loopcounter SCALEF
define loopcounter FACTOR1
define loopcounter FACTOR2
define loopcounter FACTOR3



;$Id: Delay.incl,v 1.11 2002/06/12 09:04:22 ber Exp $
# 50 "/u/exp/stan/nmr/lists/pp/cpmg-il2-hsqc-rk-fb+3919.sm.cpj" 2


;#define CARBON_LABEL 		;This version of sequence not modified to include 13C    

define delay tau		;tau_eq - Equillibrate before/after CPMG
define loopcounter k		;integer, in 2*k*cpmg_freq

;--HSQC delays--------------------
"d2=2.4m-p21-p11-10u"		; ~1/4JNH - optimize between ~2.25-2.65 ms
"d3=2.68m-p22-p11*2-15u"	;1st delay in Rance-Kay transfer
"d4=2.68m-p23-p11-15u"		;2nd delay in Rance-Kay transfer 
"d5=2.68m-p23-p11*2-15u"	;2nd delay in Rance-Kay transfer (Has 2 shape pulses on 1H)
"d14=2.68m-p16-p11-10u"		;penultimate delay in the ref. INEPT step
"d15=2.68m-p16-p11*2-15u"	;last delay in ref. INEPT - 1H/15N pulses together
"d25=p7-p1*2"			; 1H delay for ending ref. INEPT together

;--CPMG delays--------
"tau=5.0m"			;tau_eq before and after CPMG pulse train
"d18=tau-p17-p11-300u-5u"	;tau_eq =(2-3)/kex ~ 5ms
"d17=tau"			;tau_eq without Grad pulse

"d22=30m"			;T-relax, Total CPMG relaxation time

"d20=p7-p1*(2/3.1416)"		;delay zeta = pw90N - (2/pi)*pw90H

;--15N evolution delay - 0-0 phase correction------------------------
"d27=2.68m-d0*2-p26-p1*2-p12*2-10u"	;Delay in mid-evoluion
"d28=2.68m-p27-5u"			;Delay after evolution
"l0=td1/(2*23)"

;---- other delays-----------------
"d6=p8-p6"
"d9=p8*0.36"
"d11=50m"			; disk I/O
"d12=1m"			; short delay
"d0=3u"				; initial t1 dwell time
"d26=p7-p1"			; delay for centering pulses
"d7=p24+p1*0.6366-p25"
"d19=100u"
"d29=p8*0.6366"

"l4=0"

;------------Start experiment-----------------------

1 ze
2 1m 
  d11 do:f3 do:f1
  d12
3 d12
  d12
  d12
4 d12
  d12
  10u fq1:f1
;----------- "1H" Heat compensation loop for control expt. -------------

 if "l4==0"
 {
  	5u pl0:f1
	(p11:sp11 ph1:r):f1
	5u pl5:f1
	d22 cw:f1 ph0
	5u pl0:f1
	(p11:sp11 ph3:r):f1
	
        5u do:f1 		;Make sure decoupling is OFF
 }

 if "l4==1"{
   "l1=cnst5"
   goto 20
 }
  if "l4==2" {
   "l1=cnst6"
   goto 20
 }
  if "l4==3" {
   "l1=cnst7"
   goto 20
 }
  if "l4==4" {
   "l1=cnst8"
   goto 20
 }
  if "l4==5" {
   "l1=cnst9"
   goto 20
 }
  if "l4==6" {
   "l1=cnst10"
   goto 20
 }
  if "l4==7" {
   "l1=cnst11"
   goto 20
 }
  if "l4==8" {
   "l1=cnst12"
   goto 20
 }
  if "l4==9" {
   "l1=cnst13"
   goto 20
 }
  if "l4==10" {
   "l1=cnst14"
   goto 20
 }
  if "l4==11" {
   "l1=cnst15"
   goto 20
 }
  if "l4==12" {
   "l1=cnst16"
   goto 20
 }
  if "l4==13" {
   "l1=cnst17"
   goto 20
 }
  if "l4==14" {
   "l1=cnst18"
   goto 20
 }
  if "l4==15" {
   "l1=cnst19"
   goto 20
 }
  if "l4==16" {
   "l1=cnst20"
   goto 20
 }
  if "l4==17" {
   "l1=cnst21"
   goto 20
 }
  if "l4==18" {
   "l1=cnst22"
   goto 20
 }
  if "l4==19" {
   "l1=cnst23"
 }
  if "l4==20" {
   "l1=cnst24"
 }
  if "l4==21" {
   "l1=cnst25"
 }
  if "l4==22" {
   "l1=cnst26"
 }

20 1u
  "l2=l1-1"                       ;loopcounter for CPMG pulses
  "d23=(d22/(l1*2)-p8*2)/2"       ;tau_cpmg -> half delay between 15N-180 pulses
  "d24=d23-p8*0.6366"             ;First and last tau_cpmg - adjust for prec./proc. 15N-90
  "cnst1=(l1/d22)"                ;CPMG frequency
  "k=(8500*d22)/(l1*2)"           ;integer, where Spinlock field=2*k*cpmg_freq=15KHz
  "p5=1s/(8*k*cnst1)"             ;pw90H(SpinLock)
  "d8=p8-p5"                      ;delay to center CPMG 1H,15N 180 pulses
  "d21=0.159*(p5*4-p1*8)"  	  ;delay chi=(1/wSL)-(4/pi)*pw90H->(wSL/2*pi)=2*k*freq_CPMG
  if "cnst1 > 1030" goto 25	  ;Safety loop to end program if p5 is calculated wrong
  
  10u do:f3 do:f1
  10u pl1:f1
  10u pl3:f3
  10u setnmr2^0 setnmr0^34^32^33
  10u
  10u setnmr2|0 setnmr0|34|32|33
  10u
  d1				;HALF RELAXATION delay

; -------- 15N CPMG pulse Heat compensation loop (Total compensation time=30ms) --------
  "l5=(l3-l1)"		  	  ;l5 #Compensation pulses post ACQ., l5=Max 15N CPMG pulses
  if "l5 > 31" goto 25

   if "l5==0"
  {
  d22
  goto 15 
  }
  else
 {
  "d16=(d22/(l5*2)-p8*2)/2"       ;Compensation tau_cpmg -> half delay between 15N-180 pulses
  if "d16 < 200u" goto 25  
  5u pl6:f3
8 d16 				  
  (p8*2 ph1):f3 
  d16
  d16 
  (p8*2 ph1):f3
  d16
  lo to 8 times l5
  goto 15
  }
; ---- End compensation loop -----

15  5u pl3:f3
  d1				;HALF RELAXATION delay

;-------- Eliminate 15N Boltzmann magnetization ---------
;
  (p7 ph0):f3  
  5u
  p18:gp18			; gp18 = 1m, 3%
;----- Start INEPT --------------------------
  1m pl0:f1
  (p11:sp11 ph12:r):f1		;Change to shape pulse ????
  5u pl1:f1
  (p1 ph0)			;1H 90 (first)
  5u
  p21:gp21
  d2 pl0:f1
  (p11:sp11 ph12:r):f1
  5u pl1:f1
  (d26 p1*2 ph0) (p7*2 ph0):f3	;180 on both 1H and 15N
  5u pl0:f1
  (p11:sp11 ph12:r):f1
  5u pl1:f1
  p21:gp21
  d2
  (p1 ph1)			;1H 90 (second)
  5u pl0:f1 
  (p11:sp11 ph13:r):f1
  5u
  p20:gp20	     		; gp20 = 1m, 60% (dephase any transverse magnetization)
  300u				; gradient ringdown

;---- Continue with ref. INEPT----------------------
  
  (p7 ph0):f3			;15N 90 pulse
  5u
  p16:gp16
  d14 pl0:f1
  (p11:sp11 ph12:r):f1
  5u pl1:f1
  (d26 p1*2 ph0) (p7*2 ph0):f3	;Refocussed INEPT 180 pulses on both 1H and 15N
  5u pl0:f1
  (p11:sp11 ph12:r):f1
  5u pl1:f1
  p16:gp16
  d15 pl0:f1
  (p11:sp11 ph12:r):f1
  5u pl1:f1			;delay d25 adjusted to end 1H 180 and 15N 90 at the same time
  (d25 p1*2 ph0) (p7 ph1):f3	
  5u pl0:f1
  (p11:sp11 ph12:r):f1
  
;-------- Align H2O magnetization -------------

  d18 				;Equillibriate population conformers, tau_eq
  p17:gp17
  5u fq1:f1			;Hop 1H offset to amide region
  300u pl1:f1 pl6:f3
  (p1 ph4):f1
  d21				;Delay Chi
  (p1 ph0):f1
  d20				;Delay zeta
  (p1*2 ph4):f1
; ---End align H2 ----------------

; --- Set Expt# (L4), redirect to power level setting ------
  if "l4==0" goto 60		;Bypass CPMG, p6=29.56us, pl5=5.65dB

  if "l4==1" goto 61		;1 PI, 29.56us, pl20=5.65dB

  if "l4==2" goto 62		;2 PI, 29.76us, pl21=5.70dB

  if "l4==3" goto 62		;3 PI, 29.76us, pl21=5.70dB

  if "l4==4" goto 62		;3 PI, 29.76us, pl21=5.70dB

  if "l4==5" goto 62		;3 PI, 29.76us, pl21=5.70dB

  if "l4==6" goto 64		;4 PI, 30.24us, pl23=5.85dB

  if "l4==7" goto 63		;5 PI, 30.00us, pl22=5.77dB

  if "l4==8" goto 62		;6 PI, 29.76us, pl21=5.70dB

  if "l4==9" goto 62		;7 PI, 29.76us, pl21=5.70dB

  if "l4==10" goto 65		;8 PI, 31.25us, pl24=6.15dB

  if "l4==11" goto 62		;9 PI, 29.76us, pl21=5.70dB

  if "l4==12" goto 65		;10 PI, 31.25us, pl24=6.15dB

  if "l4==13" goto 65		;12 PI, 31.25us, pl24=6.15dB

  if "l4==14" goto 62		;14 PI, 29.76us, pl21=5.70dB

  if "l4==15" goto 65		;15 PI, 31.25us, pl24=6.15dB

  if "l4==16" goto 62		;18 PI, 29.76us, pl21=5.70dB

  if "l4==17" goto 65		;20 PI, 31.25us, pl24=6.15dB

  if "l4==18" goto 62		;21 PI, 29.76us, pl21=5.70dB

  if "l4==19" goto 63		;25 PI, 30.00us, pl22=5.77dB

  if "l4==20" goto 63		;25 PI, 30.00us, pl22=5.77dB

  if "l4==21" goto 63		;25 PI, 30.00us, pl22=5.77dB

  if "l4==22" goto 65		;30 PI, 31.25us, pl24=6.15dB

;---- Begin loop for NO-CPMG (L4=0)  ------------------------------------
60 2u  
  (p8 ph6):f3			;15N-90 pulse before CPMG start
  6u pl5:f1 			;Set power levels for Twin Pi pulses
  (d6 p6*2 ph0) (p8*2 ph7):f3	
  6u pl1:f1 			;Change power levels back to hard pulses
  (p8 ph0):f3			;15N-90 pulse after CPMG end
  goto 71

;---- End loop for no CPMG, Start loop for CPMG ------------------------
61 2u pl20:f1 pl6:f3		;pl20=5.65dB  @p5=29.56u
   goto 70
62 2u pl21:f1 pl6:f3		;pl21=5.70dB  @p5=29.76u
   goto 70
63 2u pl22:f1 pl6:f3		;pl22=5.77dB  @p5=30.00u
   goto 70
64 2u pl23:f1 pl6:f3		;pl23=5.85dB  @p5=30.24u
   goto 70
65 2u pl24:f1 pl6:f3		;pl24=6.15dB  @p5=31.25u
   goto 70
;66 2u pl25:f1 pl6:f3		;NOT USED
   goto 70
;67 2u pl26:f1 pl6:f3		;NOT USED

70 (p8 ph6):f3 (d9 cw ph0):f1	;15N-90 pulse before CPMG onset

;-------- Start CPMG sequence block -----------------
  
  d24 				;Start first half of CPMG loop
  (p8*2 ph1):f3
  d23

  if "l2==0" goto 10		; Goto Twin Pi pulses if #CPMGpulse=1

5 d23 				;Complete first half of CPMG loop
  (p8*2 ph1):f3
  d23
  lo to 5 times l2

10  0.1u
    0.1u do:f1			;Turn off CW Spinlock
    (d8 p5*2 ph0) (p8*2 ph7):f3	;15N-180 pulse mid-CPMG
    0.1u
    0.1u cw:f1 ph0		;Turn on CW Spinlock

  if "l2==0" goto 11		;Complete 2nd half of CPMG loop, except last one

6 d23 
  (p8*2 ph1):f3
  d23
  lo to 6 times l2

11 d23
  (p8*2 ph1):f3
  d24 pl3:f3			;End last CPMG loop, change power to 15N-hard

 (p8 ph0):f3 (d29 do):f1	;15N-90 pulse after CPMG end
71 5u pl1:f1			;Change power to 1H-hard
;---------- End CPMG, align H2O magnetization to +z -----------
  (p1*2 ph17):f1
  d20				;Delay zeta
  (p1 ph0):f1
  d21				;Delay Chi
  (p1 ph17):f1

  5u fq1:f1			;Hop 1H offset to water
  d17				;Delay tau_eq

;------- Start t1 evolution ---------

7 5u 
  p15:gp15
  300u pl3:f3			;Grad. ringdown
  (p7 ph16):f3

  d0
  p26:gp26*EA			; coherence encoding gradient, gp26 = 1m, 90%, SINE.50
  d27 pl0:f1
  (p12:sp12 ph12:r)
  5u pl1:f1
  (p1*2 ph0)
  5u pl0:f1
  (p12:sp12 ph12:r)
  d0 pl1:f1
  (p7*2 ph0):f3
  5u
  p27:gp27*EA			; coherence encoding gradient, gp26 = 1m, 90%, SINE.50
  d28
;#endif

;-------- Rance-Kay transfer back to 1H --------
  (d26 p1 ph2) (p7 ph9):f3
  5u pl0:f1
  (p11:sp11 ph15:r)  
  5u
  p22:gp22			; gp22 = 1.5m, 11%
  d3				
  (p11:sp11 ph12:r)
  5u pl1:f1
  (d26 p1*2 ph0) (p7*2 ph0):f3
  5u pl0:f1
  (p11:sp11 ph12:r)
  5u
  p22:gp22			; gp22 = 1.5m, 11%
  d3
  (p11:sp11 ph13:r)
  5u pl1:f1
  (p1 ph5) (p7 ph8):f3
  10u pl0:f1
  p23:gp23			; gp23 = 1.5m, 31%
  d4
  (p11:sp11 ph12:r)
  5u pl1:f1
  (d26 p1*2 ph0) (p7*2 ph0):f3
  5u pl0:f1
  (p11:sp11 ph12:r)
  5u
  p23:gp23			; gp23 = 1.5m, 31%
  d5
  (p11:sp11 ph12:r) 
  5u pl1:f1
  (p1 ph0)			
;--- 3-9-19 readout + coherence decoding ---
  5u pl16:f3
  p24:gp24			; coherence decoding gradient + watergate, gp24 = 202.6u+1m
  200u pl18:f1
  p28*0.231 ph10		; p28=90deg 1H pulse
  d19*2				; delay for binomial water suppression, d19=100u
  p28*0.692 ph10		
  d19*2
  p28*1.462 ph10
  d19*2
  p28*1.462 ph11
  d19*2
  p28*0.692 ph11
  d19*2
  p28*0.231 ph11
  5u
  p25:gp25
  195u
  d7
  5u setnmr2^0 setnmr0^34^32^33
  go=2 ph31 cpd3:f3
  1m do:f3
  d11 wr #0 if #0 zd
  d12*0.5 iu4			; Reset loop counter L4
  lo to 3 times 23


  d12*0.5 ip9 igrad EA
  d12*0.5 ip9
  d12*0.5 ru4
  lo to 3 times 2               ; Echo-antiecho
  d12 id0
  d12*0.5 ip16			; TPPI  
  d12*0.5 ip16
  d12*0.5 ip31
  d12*0.5 ip31
  lo to 4 times l0



25 exit
   
ph0=0	;generic
ph1=1	;generic
ph2=2	;generic
ph3=3	;generic
ph5=1	;Rance-Kay middle 1H-90 pulse
ph8=1		;Rance-Kay 15N-90 pulse in between 180-pulses
ph4=1 1 3 3	;1H-90,180 after tau to align 1H-magn
ph6=0 2		;15N-90 before CPMG
ph7=0 0 2 2	;15N-180 in middle of CPMG
ph9=0		;1st 15N-90 on Rance-Kay 
ph10=0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1	;3-9-19 pulses
ph11=2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3	;3-9-19 pulses
ph12=2		;Flipback pulses
ph13=3		;Other flip-back pulses
ph15=0		;Other flip-back pulses  
ph14=1		;Other flip-back pulses
ph16=1 1 1 1 3 3 3 3	;15N-90 before t1
ph17=3 3 1 1		;1H-90,180 after CPMG to align 1H-mag to +z
ph31=0 2 0 2 2 0 2 0 2 0 2 0 0 2 0 2



;pl1 : f1 channel - power level for pulse (default)
;pl18: f1 power during 3-9-19 (~ pl1)
;pl3 : f3 channel - power level for pulse (default)
;pl16: f3 channel - power level for CPD/BB decoupling
;pl5 : f1 power level for NO CPMG
;pl6 : f3 power  for CPMG pulses ~6 KHz ~45us pw90N
;pl20: f1 power CPMG spin lock -> wSL=2*k*freq_CPMG
;pl21: f1 power CPMG spin lock -> wSL=2*k*freq_CPMG
;pl22: f1 power CPMG spin lock -> wSL=2*k*freq_CPMG
;pl23: f1 power CPMG spin lock -> wSL=2*k*freq_CPMG
;pl24: f1 power CPMG spin lock -> wSL=2*k*freq_CPMG
;
;p1  : f1 channel - 90 degree high power pulse
;p5  : f1 channel - 90 pulse @SpinLock power level ~15KHz
;p6  : f1 Twin pulse during NO CPMG
;p7  : f3 channel - 90 degree high power pulse
;p8  : f3 channel CPMG pulse ~40us ~6 KHz B1 field
;p11 : Water flip-back pulse length
;p12 : Short (750us) flip-back pulse
;
;p20 : gradient pulse after initial INEPT
;p21 : gradient pulse during first INEPT
;p22 : 1st gradient pulse during Rance-Kay transfer
;p23 : 2nd gradient pulse during Rance-Kay transfer
;p24 : coh. dec. 102.6u, 90%, SINE.10
;p25 : coh. dec. 100.0u, 90%, SINE.10
;p26 : coh. enc. 1000u, 90%, SINE.10
;p27 : coh. enc. 1000u, 90%
;p16 : grad. pulse for ref. INEPT part
;p17 : grad. during tau_eq ~5m, before CPMG
;
;d2: initial INEPT delay; d2 + p21 = ~1/(4J)
;d3: 1st INEPT delay for Rance-Kay transfer; d3 + p22 = ~1/(4J)
;d4: 2nd INEPT delay for Rance-Kay transfer; d4 + p23 = ~1/(4J)
;d5: 2nd INEPT delay for Rance-Kay transfer; d4 + p23 + flip-back pulses = ~1/(4J)
;d7  : short echo delay before acquisition
;d8  : p8-p5
;d0  : incremented delay for t1 evolution (3u initial value)
;d1  : HALF of TOTAL relaxation delay; 
;d11 : delay for disk I/0 (50 m)
;d12 : delay for incrementing phases etc. (10m)
;d16 : tau_cpmg during heat comp.
;d19 : delay for 3-9-19 sequence =100u
;d22 : Total CPMG relaxation time~30ms
;d26 : difference between f3 and f1 90 degree pulses
;d27 : compensation delay for zero phase correction in F1
;
;d14 : penultimate delay in the refocussed INEPT
;d15 : last delay in ref. INEPT
;d18 : delay during tau_eq ~5m
;d21 : delay chi = (1/wSL) - (4/pi)*pw90H
;d20 : delay zeta = pw90N - (2/pi)*pw90H
;
;l0  : number of complex points in F1
;l1  : # CPMG pulses (always>0, control->l4=0)
;l2  : l1-1
;l3  : MAX # CPMG pulses (30)
;l4  : Control Flag, 0=NO CPMG
;l5  : (l3-l1)
;l6  : # Expts. (incl. duplicates)
;k   : Integer k, in wSL=2*k*cpmg_freq
;nd0 : 2
;cpd3: decoupling according to sequence defined by cpdprg3
;pcpd3: f3 channel - 90 degree pulse for decoupling sequence
;
;gp5 :  - Gradient pulse before t1-evol		
;gp18:  3%,  1m - Eliminate 15N Boltzmann magn.
;gp21:	       		- Grad during 1st INEPT
;gp20:  60%, 1m - Grad at end of 1st INEPT, before conv. antiphase IzSy
;gp16: 	 - Grad during refoc. INEPT
;gp17:   - Grad during tau_eq
;gp15:   - Grad before t1 evol
;gp22:	11%, 1.5m	- Grad during Rance-Kay transfer, 1st delay
;gp23:	31%, 1.5m	- Grad during Rance-Kay transfer, 2nd delay
;gpz24: 90%, 452.6u - Coherence decoding
;gpz25: 90%, 250u  - Grad after 3-9-19
;gpz26: 90%, 1m	- Coherence encoding during t1
;gpz27: 90%, 1m - Coh. dec. after t1
