  Measurement of diffuse gamma-ray emission from the Milky Way with Imaging
Atmospheric Cherenkov Telescopes (IACT) is difficult because of high level of
charged cosmic ray background and small field-of-view. We show that such a
measurement is nevertheless possible in the energy band 10-100 TeV. The minimal
charged particle background for IACTs is achieved in event selections used for
the analyses of the cosmic ray electrons. Tight cuts on the event quality in
these event selections allow to achieve the background level sufficiently low
to allow the measurements of the diffuse Galactic gamma-ray flux above 10 TeV.
We calculate the sensitivities of different types of IACT arrays for the
Galactic diffuse emission measurements and compare them with the diffuse
gamma-ray flux from different parts of the sky measured by the Fermi Large Area
Telescope below 3 TeV and with the astrophysical neutrino signal measured by
IceCube telescope. We show that deep exposure of existing IACT systems is
sufficient for detection of the diffuse flux from all the Galactic Plane up to
Galactic latitude |b|~ degrees. Medium Size Telescope array of CTA will be able
to detect the diffuse flux up 30 degree Galactic latitude. Its sensitivity will
be sufficient for detection of the gamma-ray counterpart of the Galactic
component of the IceCube astrophysical neutrino signal above 10 TeV. We also
propose that a dedicated IACT system composed of small but wide field-of-view
telescopes could be used for mapping the 10-100 TeV the diffuse gamma-ray
emission from across all the sky.
