SND@LHC is designed to perform measurements with high-energy neutrinos (100~GeV--1~TeV) 
produced at the LHC in the pseudo-rapidity region $7.2 < \eta < 8.6$. It allows 
the identification of all three flavours of neutrino interactions with high efficiency. 
The detector is located 480~m downstream of interaction point IP1 in the TI18 tunnel.

SND@LHC is a compact hybrid apparatus \cite{...}, shown in \figurename~\ref{....}. 
It consists of three parts: the veto, target and muon systems. The veto detector 
is situated in front of the target region. It is made of two vertically shifted planes 
of seven $42 \times 6 \times 1$~cm$^3$ scintillating bars and it identifies muons 
arriving from IP1. The target section contains five walls. Each wall consists of four 
units of emulsion cloud chambers (ECCs) and it is followed by a Scintillator Fibre 
tracker (SciFi) station. The muon system is placed downstream of the target. The 
electronic detectors provide the time stamp of the neutrino interaction, preselect 
the interaction region, identify muons and measure their charge and momentum.

The sub-micrometric precision of nuclear emulsions allows the detection of 
short-lived particles like tau leptons. Each ECC module is a sequence of 60 emulsion 
films, $19.2 \times 19.2$ cm$^2$, interleaved with 59 1~mm thick tungsten plates. 
Its weight is approximately 41.5~kg, adding up to 830~kg for the total target mass. 
Each SciFi station consists of five $40 \times 40$ cm$^2$ $x$-$y$ planes of staggered 
scintillating fibres with a diameter of 250~$\mu$m. To control the fading of emulsion 
films, the temperature of the target is kept at $15 \pm 1$~\textdegreesymbol~C and 
the relative humidity in 50--55\% range in a cold box enclosing the whole target 
region. The walls of the box have a borated polyethylene layer to shield against 
beam gas induced neutrons. The spatial resolution of single hits, about 50~$\mu$m, 
is sufficient to link hits with an interaction in an ECC. A time resolution of the 
order of $\sim$250~ps allows to disentangle the scattering of Feebly Interacting 
Particles (FIPs) from neutrinos.

The muon system consists of two parts: upstream (US), the first five stations, 
and downstream (DS), the last three stations. In combination with SciFi, it acts 
as a coarse sampling calorimeter ($\sim$9.5 interaction lengths), providing the 
energy measurement of hadronic jets. Each US station consists of 10 stacked horizontal 
scintillator bars of $82.5 \times 6 \times 1$~cm$^3$, similar to the upstream veto 
detector. The DS part consists of two layers of thin bars, one horizontally and one 
vertically arranged, allowing for a spatial resolution less than 1~cm. The 
scintillating planes are interleaved with 20~cm thick iron blocks.