Abstract
Beam emittance has particular importance in particle physics, because it provides information about the quality of the particle beam. There are many techniques for measuring the beam emittance, such as that proposed by Miller et al. [Report No. SLAC-PUB-3186, (A) (1983)]. This technique is based on determining the emittance by measuring the second-order moment of the beam using quadrupole pickups consisting of four symmetrical electrodes placed around the beam pipe at 90\ifmmode^\circ\else\textdegree\fi{} intervals, respectively. Based on Miller's approach, two signal processing methods are generally used to get the quadrupole moment of the beam, namely the difference over sum and the log ratio [, IEEE Nuclear Science Symposium Conference Record, N24-404, 2007, pp. 1675--1678] methods. However, these traditional methods provide results with a good accuracy only for a well centered beam. The method presented in this paper, which starts with Miller's approach, considerably reduces the impact of the dipole signal on the quadrupole moment measurement for both small and large values of the beam position. Furthermore, a methodology for the numerical determination of the sensitivity of quadrupole pickups will be presented.
Highlights
A capacitive or electrostatic pickup measures the charge collected on electrodes around the beam
Since for typical SIS-18 operation the bunch is long compared to the pickup electrodes, the numerical investigation of the modified log ratio and the traditional methods were carried out using the electrostatic solver of CST EMS, and the results are presented in the first part of this section
A method to pick up the quadrupole moment of an electrically charged particle beam was developed and presented in this paper
Summary
A capacitive or electrostatic pickup measures the charge collected on electrodes around the beam. Using a certain combination of the signal voltages induced at the electrodes, the capacitive pickup can be operated as a quadrupole pickup. This pickup consists in general of four symmetric metallic electrodes placed in the same transverse plane and is sensitive to the second-order moment of an electrically charged particle beam, namely σ2x − σ2y. Quadrupole pickups find application in several areas of accelerator physics, including in the measurement of the transverse beam emittance [1,2] and the detection of the injection mismatch causing envelope oscillations [3].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
