Protocol: Hahnecho1d  Sequence: hahnecho1d.c  Apptype: solidseq1d

Description:

A two-pulse Hahn echo with a choice of SPINAL64 or
TPPM decoupling. Uses a four phase cycle on pwX180
relative to the first pulse and receiver.

Setup:

Load a calibrated data set and select the protocol Hahnecho1d. For a new
nucleus calibrate with Onepul and then select Hahnecho1d.

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

Set aXecho = aX90 and pwXecho = pwX90.

Set t1Xecho and t2Xecho to create an echo delay.  It is helpful to set
t2Xecho < t1Xecho and use lsfid to set the top of the echo as the first
point of the fid. If using MAS be sure t1Xecho + pwXecho/2.0 = n/srate
where n is an interger.

Parameter Groups:

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.

echoX: Module: no
Sequence:  ssecho1d.c
Description: Implements a refocusing pulse with delays before and after
the pulse.
Parameters:  Sequence Page
       aXecho - amplitude of the obs pulses.
       t1Xecho - delay before the refocusing pulse.
       pwXecho - 180-degree flip on obs.
       t2Xecho - delay after the refocusing pulse.

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);
