PAC2013 - List of Authors (Campese, T.J.)

Paper	Title	Page
MOPHO25	Removal of Residual Chirp in Compressed Beams Using a Passive Wakefield Technique	291
	M.A. Harrison, G. Andonian, T.J. Campese, P. Frigola, A.Y. Murokh, F.H. O'Shea, M. Ruelas RadiaBeam, Santa Monica, USA M.G. Fedurin BNL, Upton, Long Island, New York, USA
	Funding: This is experiment is supported by an ongoing DOE Phase I Small Business Initiative for Research (SBIR) Grant, number DE–-SC0009550. The removal of residual chirp in XFELs is of paramount importance for efficient lasing. Although current S-band XFELs remove the unwanted residual chirp using off-crest acceleration after the final bunch compressor, this technique is not possible for XFELs with soft X-ray lines as there are no further accelerating structures. The off-crest dechirping technique is also expensive for future superconducting XFELs. In response, RadiaBeam Systems presents its work, building upon the theoretical work of Bane and Stupakov, in RF-free residual chirp mitigation using only passive techniques. Beam-induced longitudinal wakefields are produced with opposing corrugated plates which allow for an entirely RF-free chirp removal. Theory, engineering, and experimental results are presented. K.L.F. Bane, G. Stupakov, Nucl. Inst. Meth. 690 (2012) 106-110

THPAC32	Transverse Beam Profile Diagnostic Using Fiber Optic Array	1205
	S. Wu, R.B. Agustsson, G. Andonian, T.J. Campese, A.Y. Murokh RadiaBeam, Santa Monica, USA M.G. Fedurin, K. Kusche, R. Malone, C. Swinson BNL, Upton, Long Island, New York, USA R.K. Li UCLA, Los Angeles, California, USA
	Funding: This work is supported by U.S. D.O.E Contract Number DE-SC0000870 The fiber-mesh diagnostic (FMD) is a transverse beam profile diagnostic based on the emission and detection of Cherenkov radiation produced as a relativistic electron beam traverses through an ordered bundle of fiber optics (SiO2), arranged in a hexagonal close-pack configuration. Sub-10μm transverse beam profile resolution is attainable due to fiber optic core concentricity. Adequate SNR is achieved using a standard CCD sensor. A fiber optic taper input maximizes light collection efficiency by coupling each output channel to approximately single-pixel pitch. A v-groove holder and assembly process was developed to hold many fiber layers in the desired configuration. In this paper, we present results from a fully functional FMD prototype evaluated at the BNL ATF facility that demonstrates the efficacy of this diagnostic.

Paper

Title

Page

Removal of Residual Chirp in Compressed Beams Using a Passive Wakefield Technique

291

M.A. Harrison, G. Andonian, T.J. Campese, P. Frigola, A.Y. Murokh, F.H. O'Shea, M. Ruelas
RadiaBeam, Santa Monica, USA
M.G. Fedurin
BNL, Upton, Long Island, New York, USA

Funding: This is experiment is supported by an ongoing DOE Phase I Small Business Initiative for Research (SBIR) Grant, number DE–-SC0009550.
The removal of residual chirp in XFELs is of paramount importance for efficient lasing. Although current S-band XFELs remove the unwanted residual chirp using off-crest acceleration after the final bunch compressor, this technique is not possible for XFELs with soft X-ray lines as there are no further accelerating structures. The off-crest dechirping technique is also expensive for future superconducting XFELs. In response, RadiaBeam Systems presents its work, building upon the theoretical work of Bane and Stupakov*, in RF-free residual chirp mitigation using only passive techniques. Beam-induced longitudinal wakefields are produced with opposing corrugated plates which allow for an entirely RF-free chirp removal. Theory, engineering, and experimental results are presented.
* K.L.F. Bane, G. Stupakov, Nucl. Inst. Meth. 690 (2012) 106-110

THPAC32

Transverse Beam Profile Diagnostic Using Fiber Optic Array

1205

S. Wu, R.B. Agustsson, G. Andonian, T.J. Campese, A.Y. Murokh
RadiaBeam, Santa Monica, USA
M.G. Fedurin, K. Kusche, R. Malone, C. Swinson
BNL, Upton, Long Island, New York, USA
R.K. Li
UCLA, Los Angeles, California, USA

Funding: This work is supported by U.S. D.O.E Contract Number DE-SC0000870
The fiber-mesh diagnostic (FMD) is a transverse beam profile diagnostic based on the emission and detection of Cherenkov radiation produced as a relativistic electron beam traverses through an ordered bundle of fiber optics (SiO2), arranged in a hexagonal close-pack configuration. Sub-10μm transverse beam profile resolution is attainable due to fiber optic core concentricity. Adequate SNR is achieved using a standard CCD sensor. A fiber optic taper input maximizes light collection efficiency by coupling each output channel to approximately single-pixel pitch. A v-groove holder and assembly process was developed to hold many fiber layers in the desired configuration. In this paper, we present results from a fully functional FMD prototype evaluated at the BNL ATF facility that demonstrates the efficacy of this diagnostic.