Beam Diagnostics in Superconducting Accelerating Cavities

Beam Diagnostics in Superconducting Accelerating Cavities PDF Author: Pei Zhang
Publisher: Springer Science & Business Media
ISBN: 3319007599
Category : Science
Languages : en
Pages : 128

Get Book Here

Book Description
An energetic charged particle beam introduced to an rf cavity excites a wakefield therein. This wakefield can be decomposed into a series of higher order modes and multipoles, which for sufficiently small beam offsets are dominated by the dipole component. This work focuses on using these dipole modes to detect the beam position in third harmonic superconducting S-band cavities for light source applications. A rigorous examination of several means of analysing the beam position based on signals radiated to higher order modes ports is presented. Experimental results indicate a position resolution, based on this technique, of 20 microns over a complete module of 4 cavities. Methods are also indicated for improving the resolution and for applying this method to other cavity configurations. This work is distinguished by its clarity and potential for application to several other international facilities. The material is presented in a didactic style and is recommended both for students new to the field, and for scientists well-versed in the field of rf diagnostics.

Beam Diagnostics in Superconducting Accelerating Cavities

Beam Diagnostics in Superconducting Accelerating Cavities PDF Author: Pei Zhang
Publisher: Springer Science & Business Media
ISBN: 3319007599
Category : Science
Languages : en
Pages : 128

Get Book Here

Book Description
An energetic charged particle beam introduced to an rf cavity excites a wakefield therein. This wakefield can be decomposed into a series of higher order modes and multipoles, which for sufficiently small beam offsets are dominated by the dipole component. This work focuses on using these dipole modes to detect the beam position in third harmonic superconducting S-band cavities for light source applications. A rigorous examination of several means of analysing the beam position based on signals radiated to higher order modes ports is presented. Experimental results indicate a position resolution, based on this technique, of 20 microns over a complete module of 4 cavities. Methods are also indicated for improving the resolution and for applying this method to other cavity configurations. This work is distinguished by its clarity and potential for application to several other international facilities. The material is presented in a didactic style and is recommended both for students new to the field, and for scientists well-versed in the field of rf diagnostics.

Beam Position Diagnostics with Higher Order Modes in Third Harmonic Superconducting Accelerating Cavities

Beam Position Diagnostics with Higher Order Modes in Third Harmonic Superconducting Accelerating Cavities PDF Author: Pei Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages : 147

Get Book Here

Book Description


Using Higher Order Modes in Superconducting Accelerating Cavities for Beam Monitoring

Using Higher Order Modes in Superconducting Accelerating Cavities for Beam Monitoring PDF Author: J. May
Publisher:
ISBN:
Category :
Languages : en
Pages : 3

Get Book Here

Book Description
Dipole modes have been shown to be successful diagnostics for the beam position in superconducting accelerating cavities at the Free Electron Laser in Hamburg (FLASH) facility at DESY. By help of downmixing electronics the signals from the two higher order mode (HOM) couplers mounted on each cavity are monitored. The calibration, based on sigular value decomposition, is more complicated than in standard position monitors. Position like signals based on this calibration are currently being in the process of being included in the control system. A second setup based on digitizing the spectrum from the HOM couplers has been used for monitoring monopole modes. The beam phase with respect to the RF has been thus monitored. The position calibration measurements and phase monitoring made at the FLASH are presented.

Using Higher Order Modes in Superconducting Accelerating Cavities for Beam Monitoring

Using Higher Order Modes in Superconducting Accelerating Cavities for Beam Monitoring PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 3

Get Book Here

Book Description
Dipole modes have been shown to be successful diagnostics for the beam position in superconducting accelerating cavities at the Free Electron Laser in Hamburg (FLASH) facility at DESY. By help of downmixing electronics the signals from the two higher order mode (HOM) couplers mounted on each cavity are monitored. The calibration, based on singular value decomposition, is more complicated than in standard position monitors. Position like signals based on this calibration are currently being in the process of being included in the control system. A second setup based on digitizing the spectrum from the HOM couplers has been used for monitoring monopole modes. The beam phase with respect to the RF has been thus monitored. The position calibration measurements and phase monitoring made at the FLASH are presented.

High Precision Superconducting Cavity Diagnostics With Higher Order Mode Measurements

High Precision Superconducting Cavity Diagnostics With Higher Order Mode Measurements PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

Get Book Here

Book Description
Experiments at the FLASH facility at DESY have demonstrated that the higher order modes induced in superconducting cavities can be used to provide a variety of beam and cavity diagnostics. The axes of the modes can be determined from the beam orbit that produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used to obtain high resolution beam position information, and the phase of the monopole modes to measure the beam phase relative to the accelerator rf. For most superconducting accelerators, the existing higher order mode couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional beam position monitor.

Higher Order Mode-based Beam and Cavity Diagnostics in 1.3 GHz Superconducting Cavities at FLASH

Higher Order Mode-based Beam and Cavity Diagnostics in 1.3 GHz Superconducting Cavities at FLASH PDF Author: Junhao Wei
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description


A Study of Beam Position Diagnostics with Beam-excited Dipole Higher Order Modes Using a Downconverter Test Electronics in Third Harmonic 3.9 GHz Superconducting Accelerating Cavities at FLASH

A Study of Beam Position Diagnostics with Beam-excited Dipole Higher Order Modes Using a Downconverter Test Electronics in Third Harmonic 3.9 GHz Superconducting Accelerating Cavities at FLASH PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 54

Get Book Here

Book Description


Beam Test of a Superconducting Cavity for the Fermilab High-brightness Electron Photo-injector

Beam Test of a Superconducting Cavity for the Fermilab High-brightness Electron Photo-injector PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
An electron photo-injector facility has been constructed at Fermilab for the purpose of providing a 14 18 MeV elec-tron beam with high charge per bunch (8 nC), short bunch length (1 mm RMS), and small transverse emittance [1]. The facility was used to commission a second-generation photo-cathode RF gun for the TeSLA Test Facility (TTF) Linac at DESY [2, 3]; in the future, the Fermilab electron beam will be used for R & D in bunch length compres-sion, beam diagnostics, and new acceleration techniques. Acceleration beyond 4 MeV is provided by a 9-cell super-conducting cavity (see Figure 1). The cavity also provides a longitudinal position-momentum correlation for subse-quent bunch length compression. We report on the RF tests and a first beam test of this cavity.

Studies of Superconducting Cavities for Heavy Ion Accelerators

Studies of Superconducting Cavities for Heavy Ion Accelerators PDF Author: Peter Hutson Ceperley
Publisher:
ISBN:
Category :
Languages : en
Pages : 266

Get Book Here

Book Description


Electronics and Algorithms for HOM Based Beam Diagnostics

Electronics and Algorithms for HOM Based Beam Diagnostics PDF Author: Marc Ross
Publisher:
ISBN:
Category :
Languages : en
Pages : 12

Get Book Here

Book Description
The signals from the Higher Order Mode (HOM) ports on superconducting cavities can be used as beam position monitors and to do survey structure alignment. A HOM-based diagnostic system has been installed to instrument both couplers on each of the 40 cryogenic accelerating structures in the DESY TTF2 Linac. The electronics uses a single stage down conversion form the 1.7 GHz HOM spectral line to a 20MHz IF which has been digitized. The electronics is based on low cost surface mount components suitable for large scale production. The analysis of the HOM data is based on Singular Value Decomposition. The response of the OM modes is calibrated using conventional BPMs.