Protocol: Tancpht1  Sequence: tancpht1.c  Apptype: solidseq1d

Description: 

A proton T1 measurement using inversion recovery followed by X 
detection with constant, linear or tangent-ramped cross polarization 
(CP) between proton and X with a choice of SPINAL64 or TPPM decoupling. 
Used for proton T1 measurements with CP.  

Setup: 

Load a calibrated data set and select the protocol Tancpht1. For a new 
nucleus calibrate CP with Onepul and Tancpx and then select Tancpht1.

Select the desired decoupling method, TPPM or SPINAL. The manual file 
Onepul describes calibration of decoupling.

Set aH180 = aH90 and pwH180 = 2.0*pwH90.

Array d2 and process the data with a T1 macro. 

Parameter  Groups: 

180H:  Module:  no 
Sequence:  tancpht1.c 
Description:  Provides a 180-degree pulse on dec that can be used as 
              an inversion or a refocusing pulse.              
Parameters:  Sequence Page         
       aH180 -  the amplitude of the pulse.
       pwH180 - the pulse length. 

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);  
 
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);   
