ICAP2012 - List of Keywords (positron)

Paper	Title	Other Keywords	Page
MOACC2	Simulation of Electron Cloud Instability	electron, simulation, solenoid, betatron	26
	K. Ohmi KEK, Ibaraki, Japan
	We discuss coupled bunch and single bunch instabilities caused by electron cloud in positron and proton circular accelerator. We focus unstable mode spectrum which characterizes the instabilities.
	Slides MOACC2 [3.432 MB]

MOACC3	Tracking of a PETRA III Positron Bunch with a Pre-Computed Wake Matrix due to Electron Clouds	emittance, simulation, electron, wakefield	31
	A. Markoviḱ, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Work supported by DFG under contract number RI 814/20-2. At the synchrotron radiation facility at DESY transversal tune spectra have been observed which are characteristic for an interaction of the positron beam with possible electron clouds in the ring. The filling patterns at which this incoherent tune shifts happen are favourable to the growth of the electron density, i.e. long bunch trains with short intra-bunch distances or filling with short trains but also short distances between the trains. Eventually the vertical emittance growth with the originally designed equidistant filling (with 8 or 16 ns bunch spacing) has been avoided by fillings with shorter trains and longer gaps between the trains by still achieving the designed beam current of 100 mA. In this paper we examine the positron bunch stability of PETRA III for certain e-cloud densities and bunch parameters. A PIC simulation of the interaction of the bunch with an e-cloud yields the wake kick on the tail particles for an offset in the transverse centroid position of the head parts. With such a pre-computed wake matrix, we investigate the stability of a single bunch by tracking it through the linear optics of the ring while at each turn applying the kick from the e-cloud.
	Slides MOACC3 [5.237 MB]

Paper

Title

Other Keywords

Page

MOACC2

Simulation of Electron Cloud Instability

electron, simulation, solenoid, betatron

26

K. Ohmi
KEK, Ibaraki, Japan

We discuss coupled bunch and single bunch instabilities caused by electron cloud in positron and proton circular accelerator. We focus unstable mode spectrum which characterizes the instabilities.

Slides MOACC2 [3.432 MB]

MOACC3

Tracking of a PETRA III Positron Bunch with a Pre-Computed Wake Matrix due to Electron Clouds

emittance, simulation, electron, wakefield

31

A. Markoviḱ, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: Work supported by DFG under contract number RI 814/20-2.
At the synchrotron radiation facility at DESY transversal tune spectra have been observed which are characteristic for an interaction of the positron beam with possible electron clouds in the ring. The filling patterns at which this incoherent tune shifts happen are favourable to the growth of the electron density, i.e. long bunch trains with short intra-bunch distances or filling with short trains but also short distances between the trains. Eventually the vertical emittance growth with the originally designed equidistant filling (with 8 or 16 ns bunch spacing) has been avoided by fillings with shorter trains and longer gaps between the trains by still achieving the designed beam current of 100 mA. In this paper we examine the positron bunch stability of PETRA III for certain e-cloud densities and bunch parameters. A PIC simulation of the interaction of the bunch with an e-cloud yields the wake kick on the tail particles for an offset in the transverse centroid position of the head parts. With such a pre-computed wake matrix, we investigate the stability of a single bunch by tracking it through the linear optics of the ring while at each turn applying the kick from the e-cloud.

Slides MOACC3 [5.237 MB]