Magnetic-rigidity settings are set via CS-Studio. This program can be run on the EXP network.

Navigate from “FRIB EXP” to “S800” and to “Tune beam.” and click the “S800” button on the top right corner.

The magnetic rigidity (“Brho”) of BTS 32 & 33 (analysis beam line) of the S800 page will be set during the secondary-beam tuning (SDT) in cooperation with the AP/ARIS team. The energy loss in all detector systems (object scintillator, object PIN, tracking PPACs) operating in the analysis beam line has to be considered for the Brho setting. This requires the knowledge of the beam Brho at the exit of ARIS, which is typically calculated with the program LISE++ (follow this instructions and/or ask the AP/ARIS team for assistance). In the course of secondary-beam tuning, a scintillating target (“viewer”) and camera setup at the target position of the S800 might be requested by the A1900 group (now known as the ARIS group).

The Brho of BTS34 (spectrograph) has to be chosen by the experimenter according to the objectives of the experiment. The BTS34 can roughly be estimated by assuming the BTS33 Brho (analysis beam line) and correcting for the energy loss of the desired fragment/particle in the reaction target. The “physical calculator” of the program LISE++ is well suited for this purpose. The final Brho of BTS34 will later be fine-tuned to achieve the desired setting in the S800 focal plane (fragment of interest centered, for example). Please coordinate all required Brho changes of the spectrograph beam line (segment 8) with the A1900 group as early as possible.

We strongly recommend producing savesets (formerly known as Barney printouts) after every change of the spectrograph. This not only provides a paper copy of all magnet settings from segment 0 to segment 8 but also saves this information in ascii format on disk (accessible via the A1900 web site under Beam Line Savesets). If an inverse map is desired for the tracking of the particles in the spectrograph, BTS34 Brho and the magnet currents of the dipoles and quadrupoles are needed to determine important input parameters for the calculation.