Protocol: Super2d  Sequence: super2d.c  Apptype: solidseq1d

Description: 

X homonuclear 2D with scaled shift anisotropy in F1.

Reference:

S.-F. Liu, J-D. and K. Schmidt-Rohr, J. Magn. Reson, 155, 15-28 (2002).  
Also find additional information on the Web site of K.Schmidt-Rohr at 
Iowa State University. 

Additional Software:

reset_super2d.  This macro sets the pulse lengths and delays of superX
according to the equations below. tossX is set from aX90 and pwX90. 
sw1 is set equal to the spin rate. Parameters are set for homonuclear
2D with axis='pp'and daslp and scalesw1 for shearing. This macro 
is run with the protocol. 

Setup: 

Load a calibrated data set and select the protocol Super2d. 
For a new nucleus calibrate CP with Onepul and Tancpx and then 
run the protocol Super2d. It is best to set tof in the center 
of the spectral region (100 ppm). Run a spectrum with spin rate = 
3000 to 7000 Hz,  5000 is a good default. 

The reset macro makes the following calculations when run from 
the protocol. 

1.  Set t1Xsuper = 1/srate and round to 100 ns resolution. 
2.  Calculate t2Xsuper (taua) from the equation - 
  
 t2Xsuper = $tauafac*$tauR 

where $tauafac = 0.2464. Alternate factors can be chosen as an 
argument to the reset_super2d macro, based on Figure 2 of page 17
of the reference. Round t2Xsuper to 100 ns resolution. 

3.  Calculate pwXsuper (the 360 pulse) from the equation - 

 pwXsuper = ($tauR*0.5195 - 0.0958*$taua - 1.3917*$taua*$taua/$tauR - $taua)/2.0

as described on page 17 of the reference. Round pwXsuper to 200 ns resolution.

4.  Calculate aXsuper from aX90 and pwX90 based on the equation - 

 aXsuper = aX90*4.0*pwX90/pwXsuper

5. Calculate the scale factor chi as - 

 chi = -0.0006 + 2.0526*$x - 0.7196*$x*$x - 33.6982*$x*$x*$x +52.2845*$x*$x*$x*$x

based on page 17 of the reference. Set scalesw1 = 1/chi. chi = 0.15 
for tauafac = 0.2464. 

6. Calculate the shearing factor epsilon ("eps") as - 

 eps = 1.0 - 4.0*pwXsuper/t1Xsuper

and set daslp = 360.0*sw*(eps-chi)/sw1.  eps = 0.667 for tauafac = 0.2464
and daslp = 2879. 

Set qXsuper = 1 if ofXsuper = 0.0 (the usual condition). If ofXsuper <> 0.0
set qXsuper = ni. 

Be sure that aXsuper and pwXsuper (the 360) provide reasonable values within 
the spec of the probe and amplifier. Lower the spin rate if aXsuper is 
too high. For a constant scale factor aXsuper is roughly proportional to 
the spin rate. See figure 2 of the reference. 

Set the decoupling during superX, aHmixspinal to 25*wR - which will be a 
value around 100 kHz.  The decoupling must be at least twice the X field 
strength. Decoupling may be another limitation of SUPER for large spin 
rates. Economize on decoupling in F2 to protect the probe if narrow 
lines are not needed in F2. 

Obtain the data and process with pmode = 'partial' and with daslp set 
correctly. Transform the data with wft2da. If the carrier is
upfield or downfield use lsfrq1 to bring all resonances into the
F1 window.  Reference F2 with rl or setref and then apply the 
"shift"in ppm of one line to F1 with the equation r1(shift*sfrq/scales1).
Note that if all the shifts do not fit inthe F1 window - use 
individual values of lsfrq1 to move each line to the center of the window. 

Parameter  Groups: 

90H:  Module:  no
Sequence:  tancpx.c  
Description:  Provides a 90-degree pulse on dec that can be used 
              as a preparation pulse. Also used to store the dec 
              calibration.
Parameters:  Channels Page
       aH90  - the amplitude of the pulse.
       pwH90 - the pulse length.

cpHX:  Module:  yes
Sequence:  tancpx.c
Description:  Implements constant, linear or tangent-ramped cross 
              polarization from dec to obs. 
Parameters:  Sequence Page
       shHX - 'c', constant, 'l', linear and 't', tangent shape on
               the channel designated with chHX. 
       chHX - the variable-amplitude channel, 'fr' from or 'to', to. 
       aHhx - median amplitude of the dec channel.
       aXhx - median amplitude of the obs channel.
       bHX -  +/- tangent curvature (>0 to 1.0e5).  
       dHX -  amplitude width of the ramp. A negative width sets a
              ramp that starts high and decreases in amplitude.
       tHX -  contact time
       ofHX - overall offset on the variable channel
       frHX = 'dec' -  channel with the initial polarization (must 
              be set - not shown).           
       toHX = 'obs' -  channel with the final polarization (must be
              set - not shown). 
Implementation:  CP hx = getcp("HX",0.0,0.0,0,1); 
Underscore functions: _cp_(hx,phHhx,phXhx); 

superX: Module:  yes
Sequence:  super2d.c
Description:  Implements SUPER for Shift Anisotropy Recoupling
Parameters:  Sequence Page
       aXsuper - amplitude of obs pulses.
       pwXsuper - 360-degree flip on obs.
       t1Xsuper - one rotor period.
       t2Xsuper - "tau a" delay of the cycle.
       qXsuper - SUPER cycles represented in the .DEC file.
       ofXsuper - overall frequency offset.
       chXsuper = 'obs' must be set (not shown).
Implementation: MPSEQ super = getsuper("superX",0,0.0,0.0,0,1);
Underscore functions: _MPSEQ functions.

inczfX: Module: no 
Sequence: super2d.c 
Description: Implements an incremental ZF delay between two 90-degree
             pulses. Used to remove artifacts and improve TOSS.
Parameters:  tXinczf is internal to the sequence.  
       tXinczf - a delay that cycles between n*tauR/4.0 where n = 0,1,2,3
       on successive scans. The two 90 degree pulses use the 90X module. 

tossX:  Module:  yes
Sequence:  tancpxtoss.c
Description:  Implements four-pulse TOSS sideband suppression on obs.
Parameters:  Sequence Page
       aXtoss - amplitude of the obs pulses.
       pwXtoss - 180-degree flip on obs.
       chXtoss = 'obs' must be set (not shown).
Implementation:  WMPA toss = gettoss4("tossX");
Implementation:  WMPA toss = gettoss5("tossX");
Underscore function: _toss4(toss,phXtoss);  phXtoss is the 
              overall phase table.
Underscore function: _toss5(toss,phXtoss);  phXtoss is the 
              overall phase table.

Hmixseq:  Module: yes 
Sequence:  redor1tancp.c
Description:  Chooses SPINAL or TPPM decoupling on the dec channel
              during F1 and mixing periods when Hseq is used for
              acquisition.
Parameters:  Sequence Page - the Hmixspinal and Hmixtppm groups
              overlap.  Hmixseq chooses the decoupling sequence TPPM
              or SPINAL.
Implementation:  DSEQ mix = getdseq("H"); The router implements
              getspinal() or gettppm(), as selected.
Underscore functions:  _dseqon(mix); runs _tppm(); or _spinal();
             _dseqoff(mix); runs decprgoff(mix);

Hmixspinal:  Module: yes
Sequence:  redor1tancp.c
Description:  Implements SPINAL decoupling on the dec channel during
              typical F1 and mixing periods when Hspinal is used for
              acquisition.
Parameters:  Sequence Page
       aHmixspinal - amplitude of the dec channel.
       pwHmixspinal - approximate 180-degree flip.
       phHmixspinal - +/- small angle phase. SPINAL64 is implemented
              with phases = +/- 1.0, +/- 1.5 and +/-2.0 times
              phHmixspinal.
       chHmixspinal = 'dec' must be set (not shown).
Implementation: SPINAL mix = getspinal("H"); or DSEQ mix =
             getdseq("H");
Underscore functions: _spinal(mix); and decprgoff(); or _dseqon(mix);
             and _dseqoff(mix);
        
Hmixtppm:  Module: yes
Sequence:  redor1tancp.c
Description:  Implements TPPM decoupling on the dec channel during
              typical F1 and mixing periods when Htppm is used for
              acquisition.
Parameters:  Sequence Page
       aHmixtppm - amplitude of the dec channel.
       pwHmixtppm - approximate 180-degree flip angle on resonance.
       phHmixtppm - +/- small angle phase. TPPM is implemented
              with phases = +/- 1.0 times phHmixtppm for alternating
              pulses.
       chHmixtppm = 'dec' must be set (not shown).
Implementation: TPPM mix = gettppm("H"); or DSEQ mix = getdseq("H");
Underscore functions: _tppm(mix); and decprgoff(); or _dseqon(mix); and
              _dseqoff(mix);

Hseq:  Module:  yes 
Sequence:  tancpx.c      
Description: Chooses SPINAL or TPPM decoupling on the dec channel 
             during acquisition.
Parameters:  Sequence Page - the Hspinal and Htppm groups overlap.
       Hseq - chooses the decoupling sequence, TPPM or SPINAL. 
Implementation:  DSEQ dec = getdseq("H");  The router implements 
             getspinal() or gettppm(). 
Underscore functions: _dseqon(dec); runs _tppm(); or _spinal();_
             dseqoff(dec); runs decprgoff();  

Hspinal:  Module:  yes 
Sequence: tancpx.c  
Description:  Implements SPINAL decoupling on the dec channel during 
              acquisition.  
Parameters:  Sequence Page
       aHspinal - amplitude of the dec channel. 
       pwHspinal - approximate 180-degree flip angle on resonance. 
       phHspinal - +/- small angle phase. SPINAL64 is implemented 
              with phases = +/- 1.0, +/- 1.5 and +/-2.0 times 
              phHspinal. 
       chHspinal = 'dec' must be set (not shown).
Implementation: SPINAL dec = getspinal("H"); or DSEQ dec = 
              getdseq("H");  
Underscore functions: _spinal(dec); and decprgoff(); or 
             _dseqon(dec); and _dseqoff(dec);   

Htppm:  Module:  yes 
Sequence:  tancpx.c      
Description:  Implements TPPM decoupling on the dec channel during 
              acquisition.  
Parameters:  Sequence Page
       aHtppm - amplitude of the dec channel. 
       pwHtppm - approximate 180-degree flip angle on resonance. 
       phHtppm - +/- small angle phase. TPPM is implemented 
              with phases = +/- 1.0 times phHtppm for alternating 
              pulses.  
       chHtppm = 'dec' must be set (not shown).
Implementation: TPPM dec = gettppm("H"); or DSEQ dec = getdseq("H");   
Underscore functions: _tppmon(dec); and decprgoff(); or _dseqon(dec);
              and _dseqoff(dec);   
