  Background: The $^{14}$N(n,p)$^{14}$C reaction is of interest in neutron
capture therapy, where nitrogen-related dose is the main component due to
low-energy neutrons, and in astrophysics, where 14N acts as a neutron poison in
the s-process. Several discrepancies remain between the existing data obtained
in partial energy ranges: thermal energy, keV region and resonance region.
Purpose: Measuring the 14N(n,p)14C cross section from thermal to the resonance
region in a single measurement for the first time, including characterization
of the first resonances, and providing calculations of Maxwellian averaged
cross sections (MACS). Method: Time-of-flight technique. Experimental Area 2
(EAR-2) of the neutron time-of-flight (n_TOF) facility at CERN.
$^{10}$B(n,${\alpha}$)$^7$Li and $^{235}$U(n,f) reactions as references. Two
detection systems running simultaneously, one on-beam and another off-beam.
Description of the resonances with the R-matrix code sammy. Results: The cross
section has been measured from sub-thermal energy to 800 keV resolving the two
first resonances (at 492.7 and 644 keV). A thermal cross-section
(1.809$\pm$0.045 b) lower than the two most recent measurements by slightly
more than one standard deviation, but in line with the ENDF/B-VIII.0 and
JEFF-3.3 evaluations has been obtained. A 1/v energy dependence of the cross
section has been confirmed up to tens of keV neutron energy. The low energy
tail of the first resonance at 492.7 keV is lower than suggested by evaluated
values, while the overall resonance strength agrees with evaluations.
Conclusions: Our measurement has allowed to determine the $^{14}$N(n,p)
cross-section over a wide energy range for the first time. We have obtained
cross-sections with high accuracy (2.5 %) from sub-thermal energy to 800 keV
and used these data to calculate the MACS for kT = 5 to kT = 100 keV.
