calc_adc_timing

calc_adc_timing#

pypulseqpp.calc_adc_timing()[source]#

Choose an ADC dwell whose acquisition duration is a multiple of the gradient raster.

Search upward from the nearest ADC-raster dwell that meets the duration floor, and return the first whose acquisition duration is a whole number of gradient raster periods. The receiver bandwidth achieved is 1 / dwell.

If the bounded search finds no common-raster solution, the returned duration may be off the gradient raster; check it before constructing events.

Parameters:

  • num_samples (int) – Number of ADC samples (>= 1).

  • target_dwell (float) – Requested dwell time (s), the reciprocal of the requested receiver bandwidth.

  • grad_raster_time (float) – Gradient raster (s), e.g. system.grad_raster_time.

  • adc_raster_time (float) – ADC raster (s), e.g. system.adc_raster_time.

  • min_readout_duration (float, default=0.0) – Lower bound on the returned duration (s), e.g. to fit a flat top.

Returns:

  • dwell (float) – Feasible dwell time (s), a multiple of adc_raster_time.

  • duration (float) – num_samples * dwell (s).

Raises:

ValueError – If the sample count, dwell or rasters are not positive, or the duration floor is negative.

Examples

>>> import pypulseqpp as pp
>>> dwell, duration = pp.calc_adc_timing(
...     96, 3.7e-6, grad_raster_time=10e-6, adc_raster_time=100e-9
... )
>>> round(dwell * 1e6, 4), round(duration * 1e6, 4)
(5.0, 480.0)
>>> round(duration / 10e-6, 6)
48.0

See also

make_adc

build the ADC event from the returned dwell.

calc_adc_segments

split a long ADC into equal segments.