LINAC2014 - List of Keywords (bunching)

Paper	Title	Other Keywords	Page
MOPP034	Beam Dynamics Studies of the CLIC Drive Beam Injector	emittance, cavity, focusing, quadrupole	131
	S. Sanaye Hajari, S. Döbert, H. Shaker CERN, Geneva, Switzerland S. Sanaye Hajari, H. Shaker IPM, Tehran, Iran
	In the Compact Linear Collider (CLIC) the RF power for the acceleration of the Main Beam is extracted from a high-current Drive Beam that runs parallel with the main linac. The beam in the Drive Beam Accelerator is phase coded. This means only every second accelerator bucket is occupied. However, a few percent of particles are captured in wrong buckets, called satellite bunches. The phase coding is done via a sub-harmonic bunching system operating at a half the acceleration frequency. The beam dynamics of the Drive Beam injector complex has been studied in detail and optimised. The model consists of a thermionic gun, the bunching system followed by some accelerating structures and a magnetic chicane. The bunching system contains three sub-harmonic bunchers, a prebuncher and a tapered travelling wave buncher all embedded in a solenoidal magnetic field. The simulation of the beam dynamics has been carried out with PARMELA with the goal of optimising the overall bunching process and in particular decreasing the satellite population and the beam loss in magnetic chicane and in transverse plane limiting the beam emittance growth.

THPP030	Status of the Design Study for 10 MHz Post-accelerated Radioactive Ion Beams at HIE-ISOLDE	rfq, emittance, linac, ion	901
	M.A. Fraser, R. Calaga CERN, Geneva, Switzerland
	A ten-fold increase in the bunch spacing of post-accelerated radioactive ion beams has been requested by several research groups at ISOLDE, CERN in order for experiments to use time-of-flight particle identification and background suppression techniques. It is proposed to bunch externally into the existing REX-ISOLDE RFQ at a sub-harmonic frequency of 10.128 MHz to produce the desired 100 ns bunch separation with minimal loss in transmission. The status of a beam dynamics design study carried out to meet this request will be presented in the framework of the HIE-ISOLDE linac upgrade at CERN.

THPP136	Study of Femtosecond Electron Bunch Generation at t-ACTS, Tohoku University	electron, gun, injection, radiation	1178
	S. Kashiwagi, H. Hama, F. Hinode, A. Lueangaramwong, T. Muto, I. Nagasawa, S. Nagasawa, K. Nanbu, Y. Shibasaki, K. Takahashi, C. Tokoku Tohoku University, Research Center for Electron Photon Science, Sendai, Japan N.Y. Huang NSRRC, Hsinchu, Taiwan
	We are conducting a beam experiment of sub-picosecond electron bunch generation at a test accelerator as a coherent terahertz source (t-ACTS), Tohoku University. In the t-ACTS, the intense coherent terahertz radiation will be generated from an undulator and an isochronous accumulator ring based on the sub-picoseconds bunches. The accelerator is composed of a thermionic cathode rf gun, alpha magnet and 3 m-long accelerating structure. A velocity bunching scheme in accelerating structure is applied to generate the short electron bunch. The thermionic rf gun consists two independent cavities has been developed, which is capable of manipulating the beam longitudinal phase space. To produced femtosecond electron bunch, the longitudinal phase space distribution of the beam entering the accelerating structure is optimized by changing the rf gun parameters. The bunch length is measured by observing an optical tradition radiation with a streak camera. In the study of femtosecond electron bunch generation, a relation between the rf gun parameters and the bunch length after compression was investigated. The preliminary results of experiments will be described in this conference.

Paper

Title

Other Keywords

Page

MOPP034

Beam Dynamics Studies of the CLIC Drive Beam Injector

emittance, cavity, focusing, quadrupole

131

S. Sanaye Hajari, S. Döbert, H. Shaker
CERN, Geneva, Switzerland
S. Sanaye Hajari, H. Shaker
IPM, Tehran, Iran

In the Compact Linear Collider (CLIC) the RF power for the acceleration of the Main Beam is extracted from a high-current Drive Beam that runs parallel with the main linac. The beam in the Drive Beam Accelerator is phase coded. This means only every second accelerator bucket is occupied. However, a few percent of particles are captured in wrong buckets, called satellite bunches. The phase coding is done via a sub-harmonic bunching system operating at a half the acceleration frequency. The beam dynamics of the Drive Beam injector complex has been studied in detail and optimised. The model consists of a thermionic gun, the bunching system followed by some accelerating structures and a magnetic chicane. The bunching system contains three sub-harmonic bunchers, a prebuncher and a tapered travelling wave buncher all embedded in a solenoidal magnetic field. The simulation of the beam dynamics has been carried out with PARMELA with the goal of optimising the overall bunching process and in particular decreasing the satellite population and the beam loss in magnetic chicane and in transverse plane limiting the beam emittance growth.

THPP030

Status of the Design Study for 10 MHz Post-accelerated Radioactive Ion Beams at HIE-ISOLDE

rfq, emittance, linac, ion

901

M.A. Fraser, R. Calaga
CERN, Geneva, Switzerland

A ten-fold increase in the bunch spacing of post-accelerated radioactive ion beams has been requested by several research groups at ISOLDE, CERN in order for experiments to use time-of-flight particle identification and background suppression techniques. It is proposed to bunch externally into the existing REX-ISOLDE RFQ at a sub-harmonic frequency of 10.128 MHz to produce the desired 100 ns bunch separation with minimal loss in transmission. The status of a beam dynamics design study carried out to meet this request will be presented in the framework of the HIE-ISOLDE linac upgrade at CERN.

THPP136

Study of Femtosecond Electron Bunch Generation at t-ACTS, Tohoku University

electron, gun, injection, radiation

1178

S. Kashiwagi, H. Hama, F. Hinode, A. Lueangaramwong, T. Muto, I. Nagasawa, S. Nagasawa, K. Nanbu, Y. Shibasaki, K. Takahashi, C. Tokoku
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
N.Y. Huang
NSRRC, Hsinchu, Taiwan

We are conducting a beam experiment of sub-picosecond electron bunch generation at a test accelerator as a coherent terahertz source (t-ACTS), Tohoku University. In the t-ACTS, the intense coherent terahertz radiation will be generated from an undulator and an isochronous accumulator ring based on the sub-picoseconds bunches. The accelerator is composed of a thermionic cathode rf gun, alpha magnet and 3 m-long accelerating structure. A velocity bunching scheme in accelerating structure is applied to generate the short electron bunch. The thermionic rf gun consists two independent cavities has been developed, which is capable of manipulating the beam longitudinal phase space. To produced femtosecond electron bunch, the longitudinal phase space distribution of the beam entering the accelerating structure is optimized by changing the rf gun parameters. The bunch length is measured by observing an optical tradition radiation with a streak camera. In the study of femtosecond electron bunch generation, a relation between the rf gun parameters and the bunch length after compression was investigated. The preliminary results of experiments will be described in this conference.