1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Coherent transfer of hyperpolarization in coupled spin systems at variable magnetic field
Rent:
Rent this article for
USD
10.1063/1.2901019
/content/aip/journal/jcp/128/15/10.1063/1.2901019
http://aip.metastore.ingenta.com/content/aip/journal/jcp/128/15/10.1063/1.2901019
View: Figures

Figures

Image of FIG. 1.
FIG. 1.

Timing scheme of HP formation in field-cycling experiment. HP is created during time period (step 1, preparation) at magnetic field ; it freely evolves at the polarization field during time period (step 2, evolution); then during time period the polarized spins are subject to a magnetic field switch from to the detection field (step 3, field variation); here the polarized Fourier transform NMR spectrum is recorded (step 4, detection).

Image of FIG. 2.
FIG. 2.

Dependence of the HP transfer efficiency on magnetic field in sudden (a) and adiabatic (b) regimes of field variation. Only the first spin (solid line) is polarized directly, while the second (dashed line) and the third spin (dotted line) acquire HP in the transfer process. All coherences are set to zero , polarizations of individual nuclei are normalized that . At detection field spins are assumed weakly coupled. Parameters of the spin system: , , and for chemical shifts and , , and for couplings. Arrows indicate the position of the level anticrossing at .

Image of FIG. 3.
FIG. 3.

Dependence of HP on the evolution time (a) and preparation time (b). Only the first spin (solid line) is polarized directly, while the second (dashed line) and the third one (dotted line) acquire HP in the transfer process. Polarizations of individual nuclei, are normalized that . Switching to high detection field (spins are weakly coupled at ) is assumed to be sudden. In (a) is assumed to be negligibly short, in (b) is set to zero. couplings: , , , field is so small that the difference are negligible as compared to .

Image of FIG. 4.
FIG. 4.

Dependence of the HP transfer efficiency on magnetic field calculated for different preparation times. Only the first spin (solid line) is polarized directly, whereas the second (dashed line) and the third spin (dotted line) acquire HP in the transfer process. The preparation time is (a), (b), (c), and (d); evolution time is zero, field variation is sudden. Polarizations of individual nuclei, , are normalized that . At detection field spins are assumed weakly coupled. Parameters of the spin system are the same as those for Fig. 2.

Image of FIG. 5.
FIG. 5.

Dependence of the HP transfer efficiency on magnetic field calculated for different evolution times. Only the first spin (solid line) is polarized directly, the second (dashed line) and the third (dotted line) acquire HP in the transfer process. Evolution time is (a); (b); (c); and (d); preparation time is , field variation is sudden. Polarizations of individual nuclei, , are normalized that . At detection field spins are assumed weakly coupled. Parameters of the spin system are the same as those for Fig. 2.

Image of FIG. 6.
FIG. 6.

Dependence of the HP transfer efficiency on magnetic field in sudden (a) and adiabatic (b) regimes of field variation demonstrating HP transfer in the absence of direct coupling between the spins. Only the first spin (solid line) is polarized directly, whereas the second (dashed line) and the third (dotted line) spins acquire HP in the transfer process. All coherences are set to zero, polarizations of individual nuclei , are normalized that ; at detection field spins are assumed weakly coupled. Parameters of the spin system: Chemical shifts , , ; couplings: , ; direct coupling between the first and the third spins is set zero . Arrows indicate the position of the level anticrossing at .

Image of FIG. 7.
FIG. 7.

Dependence of HP on evolution time (a) and preparation time (b) in the absence of direct coupling between the directly polarized spin and one of the other two spins . Only the first spin (solid line) is polarized directly, while the second (dashed line) and the third (dotted line) acquire HP in the transfer process. Polarizations of individual nuclei, , are normalized . Transfer to high detection field (spins are weakly coupled at ) is assumed to be sudden. In (a) is assumed to be negligibly short, in (b) is set to zero. couplings: , , ; field is so small that .

Image of FIG. 8.
FIG. 8.

Field dependence of PHIP in a three-spin system calculated in sudden (a) and adiabatic (b) regimes of field variation. The first spin (solid line) and second spin (dashed line) are initially prepared in their singlet state, whereas the third spin (dotted line) acquires HP indirectly. All coherences were set to zero; polarizations of the individual nuclei, , are normalized to the initial population of the singlet state. At detection field spins were assumed weakly coupled, parameters of the spin system are the same as those in Fig. 6. Arrows indicate the position of the level anticrossing at .

Loading

Article metrics loading...

/content/aip/journal/jcp/128/15/10.1063/1.2901019
2008-04-15
2014-04-18
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Coherent transfer of hyperpolarization in coupled spin systems at variable magnetic field
http://aip.metastore.ingenta.com/content/aip/journal/jcp/128/15/10.1063/1.2901019
10.1063/1.2901019
SEARCH_EXPAND_ITEM