QCLAM

QCLAM

This figure shows the composition of the QClam spectrometer. There are two indispensable components. First of all there is a large dipole magnet, which deflects electrons with different energies onto different paths. This allows the reconstruction of the electron energies by use of position sensitive detectors. The second critical component is the detector setup of the spectrometer. It consists of three position sensitive wire chambers, a cherenkov counter and a scintillator. The data from the wire chambers together with the starting signal generated by the scintillator are used to gather the experimentally relevant data, while the cherenkov counter is used for background reduction purposes.

The QClam is one of two magnet spectrometers at the S- DALINAC. It is used for (e,e') and (e,e'x) experiments at various incident beam energies and scattering angles. Electrons which have been scattered from a target nucleus will enter the spectrometer and be deflected by the pentapole and dipole magnet according to their respective impulse. These electrons can then be detected by the position sensitive wire chambers and their energy and scattering angle can be reconstructed.

The 180° scattering beamline consists of a schicane and a seperation magnet. The incoming electron beam is deflected by a dipole magnet into the schicane and is later deflected into the scattering chamber by another dipole magnet. The central point of the scattering chamber is now occupied by a seperation magnet, which deflects the incoming beam back in it's original direction. The beam then impinges on the target, which has been moved a bit towards the faraday cup. Electron scattered by 180° from the target then pass the seperation magnet again and are deflected into the QClam spectrometer.

Additionally it is possible to operate the QClam in 180 degree mode using the schicane. This allows the detection of electrons scattered by 180 degrees, which results in a suppression of longitudinal excitations and thus presents a unique opportunity to study weak vertical excitations.