Protocol: Tancpxflip  Sequence: tancpxflip.c  Apptype:  solidseq1d

Description: 

Constant, linear or tangent-ramped cross polarization (CP) between 
protons and X with an X flip-back pulse and a choice of SPINAL64 or 
TPPM decoupling. Used for calibration of pwX90 with CP. 

Setup:

Load a calibrated data set and select the protocol Tancpxflip. For a 
new nucleus calibrate CP with Onepul and Tancpx and then select 
Tancpxflip.  
   
Select the desired decoupling method, TPPM or SPINAL. The manual file 
onepul describes calibration of decoupling.

Array pwX90 to obtain a pulse width calibration. The signal is nulled 
for flip angles of 90 and 270 degrees. 

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);  

90X:   Module:  no
Sequence:   onepul.c    
Description:  Provides a 90-degree pulse on obs that can be used as a 
preparation pulse. 
                      Also used to store the obs calibration.
Parameters:  Channels Page
      aX90  - the amplitude of the pulse.
      pwX90 - the pulse length.
 
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);   
   
