Beam Loss Calculation Of Cyclotron And Performance Study Of Beam Loss Monitor

With the development of accelerators,Beam loss monitor is widely used during the operation and modification of accelerators.Because the installation position of beam loss monitor has great effects on its accuracy,it's essential to perform a careful study of beam loss distribution before installing the BLM.In this paper,G4 beamline program was used to calculate the beam loss distribution of a H-cyclotron beam line.And the types of secondary particles and their distribution along the beam line as well as the space charge effects on beam loss are also discussed in this thesis.This calculation provides reliable position information for the installation of beam loss monitor in this aiming beam line.Meanwhile,some tests have been done to test the characteristics of beam loss monitor including the calibration of the plateau curve of BLM,relationships between beam intensity and BLM signal,the effects of quadrupole magnetic strength change and faraday cup measurements on BLM signal.And another experiment was performed to figure out its reflection ability to the change of beam direction.The result shows that in horizontal direction,the reflection ability of BLM to beam direction is different.With respect to the signal difference appeared in the experiment,an optimization scheme was presented: the signal difference could be reduced by the joint effects of stripper position adjustments and steering.Both experiments and simulation calculation has been performed to verify the feasibility of the optimization scheme.The result proved the new method is feasible and the relationships between bending angle and beam centroid position and beam loss monitor signal are provided.