The BGO-OD experiment emerged from the B.1 project of a magnetic spectrometer, originally intended to be used in combination with Crystal Barrel to detect forward going charged particles with high resolution over a large acceptance. The main device is a 94 t large-aperture dipole magnet , the “open dipole” (OD). Shortly after the previous review of the CRC 16 a major part of the former GRAAL group joined the spectrometer project.
This lead to the formation of the international BGO-OD collaboration in March 2010 with currently 62 members of institutions from Basel University, Bonn University (HISKP and PI), Edinburgh University, INFN Frascati, PNPI Gatchina, Gießen University, Kharkov University, Messina University and INFN, Moscow University, Pavia University and INFN, Rome “Tor Vergata” and INFN, and Torino University and INFN. In particular the Italian groups contribute very signiﬁcantly to the BGO-OD experiment, most importantly through the 480 channel BGO ball which was previously used at the ESRF Grenoble and in the meanwhile is installed with upgraded electronics at the photon beamline S of ELSA. The BGO ball encloses the cryogenic target over the angular range from 25–155◦, complemented by detectors for charge recognition and tracking. Forward directions are covered by the OD spectrometer. The magnet is sandwiched by tracking detectors and complemented by a time-of-ﬂight (TOF) spectrometer. The small acceptance gap between the spectrometer and BGO ball will be soon closed by a special MRPC, which is presently under construction at Rome. Further trackers on Si strip basis are part of this application (see project B.8). They will further improve both tracking and vertex reconstruction, and enable recoil proton polarimetry in prevalent reaction channels. Generally, the BGO-OD setup is ideally suited for unpolarised target experiments with complex ﬁnal states including both charged and neutral mesons, hence ideal to pursue strangeness and vector meson production.
The B.1 project is a part of the
Sonderforschungsbereich / Transregio 16 - Subnuclear Structure of Matter.
At the centre of the SFB/TR is the accelerator facility
at the Physikalischen Institut
of the Rheinischen Friedrich-Wilhelms-Universität Bonn.
The groups and organisations involved in the BGO-OD experiment are coming from russia, ukraine, italy and germany: