Structure of the SHiP Experiment

Location

The SHiP Experiment is located at the CERN North Area, in the ECN3 underground cavern, as successor of the NA62¹² ("North Area 62") experiment. As the successor it was given the name "NA67" (North Area 67). The ECN3 hall is located together with the TCC8 target area entirely below the ground, covered by a \(8\,\text{m}\) layer of earth⁴. The location of the experiment in the cavern can be seen in the schematic overview of the SHiP experiment in Fig. 1.

Setup

SHiP is a fixed-target experiment, using a \(400\,\text{GeV}\) beam-dump from the SPS (Super Proton Synchrotron) to produce a large number of hadrons, which then decay into long-lived particles. The setup consists of several components:

A heavy Target to produce a large number of hadrons (pions, kaons, D and B mesons) from the proton beam to yield Feebly Interacting Particles (FIPs).
A hadron absorber to stop the hadrons and reduce the background.
A Muon Shield to deflect myons away from the detector.
A Scattering and Neutrino Detector
An "Upstream Background Tagger" (UBT) to detect particles that are produced in the target and pass through the muon shield.
The Hidden Sector Decay Spectrometer (HSDS) to detect the decay of long-lived particles in flight.
- The HSDS is surrounded by a "Surround Background Tagger" (SBT) and is equipped with an "Upstream Background Tagger" (UBT) to reject background events
- At the downstream end of the HSDS vessel, a Tracker with a Magnet, a High-Precision Timing Detector (HPTD), a Calorimeter and a Muon System are used to reconstruct the decay products of the long-lived particles.

A schematic overview of the SHiP experiment is shown in Fig. 1 and Fig. 2.

**Fig. 1:** Overview of the structure and the components of the SHiP experiment within the underground cavern³.

**Fig. 2:** A schematic of the structure of the SHiP Experiment with its components. © Michael Hohenstein

The following diagram summarizes the structure of the SHiP experiment and its components:

flowchart TD

    A["Target Complex"] --> B["Hadron Absorber"]
    B --> C["Muon Shield"]
    C --> D["Scattering and Neutrino Detector"]
    D --> E["Upstream Background Tagger (UBT)"]
    E --> F["Decay Volume"]
    E --> G["Surround Background Tagger (SBT)"]
    subgraph " " 
    H["Tracker and Magnet"]
    F --> H
    H --> I["High-Precision Timing Detector (HPTD)"]
    I --> J["Electromagnetic Calorimeter (ECal)"]
    J --> K["Hadronic Calorimeter (HCal)"]
    K --> L["Muon System"]
    end