Ion mobility (IMS)

SYNAPT-class instruments produce ion-mobility data via Encoding B, in which each scan is subdivided into mobility cells (sub-bins) keyed by drift time. read_ims_spectrum returns the full flat spectrum with a per-peak drift_time_ms column.

use openwraw::RawReader;

let r = RawReader::open("synapt.raw")?;
let ims = r.read_ims_spectrum(1, 0)?;
for (mz, dt, intensity) in itertools::izip!(&ims.mz, &ims.drift_time_ms, &ims.intensity) {
    println!("{mz:.4}\t{dt:.3}\t{intensity:.0}");
}

In Python the same data is exposed via NumPy arrays:

ims = r.read_ims_spectrum(1, 0)
print(ims.mz.dtype, ims.drift_time_ms.shape, ims.intensity.shape)

The drift time is derived from the sub-bin index and the pusher interval reported by _extern.inf (the a_us field).