MEASURING THE LONGITUDINAL BUNCH PROFILE AT CTF3 (original) (raw)

Measuring the bunch frequency multiplication at the 3rd CLIC Test Facility

2012

ABSTRACT: The CLIC Test Facility 3 (CTF3) is being built and commissioned by an international collaboration to test the feasibility of the proposed Compact Linear Collider (CLIC) drive beam generation scheme. Central to this scheme is the use of RF deflectors to inject bunches into a delay loop and a combiner ring, in order to transform the initial bunch frequency of 1.5 GHz from the linac to a final bunch frequency of 12GHz.

BUNCH LENGTH MEASUREMENTS IN CTF3

Abstract The CLIC Test Facility CTF3, being built at CERN by an international collaboration, should demonstrate the feasibility of the CLIC two-beam technology by 2010. One of the issues addressed is the control of the electron bunch length in the whole complex. A bunch length measurement system, with a good resolution, is therefore paramount. Two different systems are presently used in CTF3 based on microwave spectroscopy and on transverse rf deflectors, respectively.

Development of a bunch frequency monitor for the Preliminary Phase of the CLIC Test Facility CTF3

DIPAC, 2003

In the framework of the CLIC RF power source studies, the feasibility of the electron bunch train combination by injection with RF deflectors into an isochronous ring has been successfully demonstrated in the preliminary phase of CTF3. A new method, based on beam frequency spectrum analysis, was experimented to monitor this scheme. A coaxial pick-up and its read-out electronics were designed and mounted in the CTF3 ring to allow comparison of the amplitudes of five harmonics of the fundamental beam frequency (3 GHz) while combining the bunch trains. The commissioning of the monitor was a successful proof of principle for this new method, despite the short length of the bunch trains and the presence of parasitic signals associated to high-order waveguide modes propagating with the beam inside the pipe.

Beam dynamics for the preliminary phase of the new CLIC Test Facility (CTF3)

2001

In the framework of the CLIC (Compact Linear Collider) RF power source studies, the scheme of electron pulse compression and bunch frequency multiplication, using injection by RF deflectors into an isochronous ring, will be tested, at low charge, during the preliminary phase of the new CLIC Test Facility (CTF3) at CERN. In this paper, we describe the beam dynamics studies made in order to assess the feasibility of the bunch combination experiment, as well as the related beam measurements performed on the LEP Pre-Injector complex (LPI) before its transformation into CTF3.

Non-destructive single shot bunch length measurements for the CLIC Test Facility 3

… Conference (PAC 07 …, 2007

A non-destructive bunch length detector has been installed in the CLIC Test Facility (CTF3). Using a series of down-converting mixing stages and filters, the detector analyzes the power spectrum of the electromagnetic field picked-up by a single waveguide. This detector evolved from an earlier system which was regularly used for bunch length measurements in the previous CLIC Test Facility, namely CTF2 . Major improvements are increase of frequency reach from 90 GHz to 170 GHz, allowing for sub-ps sensitivity, and single shot measurement capability using FFT analysis from large bandwidth waveform digitisers. The results of the commissioning of the detector in 2006 are presented.

Bunch frequency multiplication in the CLIC Test Facility CTF3

2003

The aim of the CLIC Test Facility CTF3 at CERN is to prove the feasibility of key issues of the two-beam based Compact Linear Collider (CLIC) study. In particular, it addresses the generation of a drive beam with the appropriate time structure to produce high power RF pulses at a frequency of 30 GHz.

Beam Tests at the CLIC Test Facility, CTF3

2014

The CLIC Test Facility CTF3 has been built at CERN by the Compact Linear Collider (CLIC) International Collaboration, in order to prove the main feasibilit y issues of the two-beam acceleration technology on which the collider is based. After the successful completion of its initial task, CTF3 is continuing its experimental prog ram in order to give further indications on cost and performance issues, to act as a test bed for the CLIC technology, and to conduct beam experiments aimed at mitigating technological risks. In this paper we di scuss the status of the ongoing experiments and present the more recent results, including improvements in beam quality and stability .

Coherent Synchrotron Radiation Measurements in the CLIC Test Facility (CTF II)

Linac 2000, 2000

Bunches of high charge (up to 10 nC) are compressed in length in the CTF II magnetic chicane to less than 0.2 mm rms. The short bunches radiate coherently in the chicane magnetic field, and the horizontal and longitudinal phase space density distributions are affected. This paper reports the results of beam emittance and momentum measurements. Horizontal and vertical emittances and momentum spectra were measured for different bunch compression factors and bunch charges. In particular, for 10 nC bunches, the mean beam momentum decreased by about 5% while the FWHM momentum spread increased from 5% to 19%. The experimental results are compared with simulations made with the code TraFiC 4 .