Module normalization 

Transmission normalization from raw neutron counts.

Converts raw sample and open-beam (OB) neutron counts into a transmission spectrum, following the ORNL Method 2 approach used in PLEIADES.

Method 2 Normalization

For each TOF bin and pixel:

T[tof, y, x] = (C_sample / C_ob) × (PC_ob / PC_sample)

where:

• C_sample = raw sample counts (dark-current subtracted)
• C_ob = open-beam counts (dark-current subtracted)
• PC_sample = proton charge for sample run
• PC_ob = proton charge for open-beam run

The proton charge ratio corrects for different beam exposures.

Uncertainty

Assuming Poisson counting statistics:

σ_T / T = √(1/C_sample + 1/C_ob)

PLEIADES Reference

• processing/normalization_ornl.py — Method 2 implementation

Structs

NormalizationParams

Parameters for transmission normalization.

NormalizedData

Result of normalization: transmission and its uncertainty.

Functions

average_roi

Average spectra over a rectangular region of interest.

detect_dead_pixels

Detect dead pixels (zero counts across all TOF bins).

extract_spectrum

Extract a single spectrum (all TOF bins) from a pixel in the 3D array.

normalize

Normalize raw data to transmission using Method 2.