IPAC2012 - List of Authors (Koizumi, G.M.)

Paper	Title	Page
MOPPC039	Electron Recombination in a Dense Hydrogen Plasma	217
	B.T. Freemire, P.M. Hanlet IIT, Chicago, Illinois, USA M. Chung Handong Global University, Pohang, Republic of Korea M.G. Collura Politecnico di Torino, Torino, Italy M.R. Jana, C. Johnstone, T. Kobilarcik, G.M. Koizumi, M.A. Leonova, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, Y. Torun, K. Yonehara Fermilab, Batavia, USA R.P. Johnson Muons, Inc, Batavia, USA
	Funding: US DOE under contract DE-AC02-07CH11359. A high pressure hydrogen gas filled RF cavity was subjected to an intense proton beam to study the evolution of the beam induced plasma inside the cavity. The electron recombination rate with the dense ionized hydrogen plasma has been measured under varying conditions. Recombination rates as high as 10^-7 cm³/s have been recorded. This technique shows promise in the R&D program for a muon accelerator. The use of hydrogen, both as a way to prevent breakdown in an RF cavity and as a mechanism for cooling a beam of muons, will be discussed.

MOPPR070	Beam Profile Measurement in MTA Beam Line for High Pressure RF Cavity Beam Test	948
	M.R. Jana, A.D. Bross, S. Geer, C. Johnstone, T. Kobilarcik, G.M. Koizumi, M.A. Leonova, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, K. Yonehara Fermilab, Batavia, USA M. Chung Handong Global University, Pohang, Republic of Korea M.G. Collura Politecnico di Torino, Torino, Italy B.T. Freemire, P.M. Hanlet, Y. Torun IIT, Chicago, Illinois, USA
	Funding: This work is supported by the United States Department of Energy under contract DE-AC02-07CH11359. The recent High Pressure RF (HPRF) cavity experiment at the MuCool Test Area (MTA) used a 400 MeV Linac proton beam to study the beam loading effect. When the energetic proton beam passes through the cavity, it ionizes the inside gas and produces electrons. These electrons consume RF power inside the cavity. The number of electrons produced per cm inside the cavity (at 950 psi Hydrogen gas) per incident proton is 1200. The measurement of beam position and profile are necessary. The MTA is a flammable gas (Hydrogen) hazard zone, so we have developed a passive beam diagnostic instrument using a Chromox-6 scintillation screen and CCD camera. This paper presents quantitative information about beam position and beam profile. A neutral density filter was used to avoid saturation of the CCD camera. Image data is filtered and fitted with a Gaussian function to compute the beam size. The beam profile obtained from the scintillation screen will be compared with a multi-wire beam profile.

TUPPC044	Emittance and Phase Space Tomography for the Fermilab Linac	1263
	C. Johnstone, F.G.G. Garcia, T. Kobilarcik, G.M. Koizumi, C.D. Moore, D.L. Newhart Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Dept. of Energy. The Fermilab Linac delivers a variable intensity, 400-MeV beam to the The MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a de-convolution of the profile data. Preliminary measurements using this diagnostic section are reported here.

Paper

Title

Page

Electron Recombination in a Dense Hydrogen Plasma

217

B.T. Freemire, P.M. Hanlet
IIT, Chicago, Illinois, USA
M. Chung
Handong Global University, Pohang, Republic of Korea
M.G. Collura
Politecnico di Torino, Torino, Italy
M.R. Jana, C. Johnstone, T. Kobilarcik, G.M. Koizumi, M.A. Leonova, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, Y. Torun, K. Yonehara
Fermilab, Batavia, USA
R.P. Johnson
Muons, Inc, Batavia, USA

Funding: US DOE under contract DE-AC02-07CH11359.
A high pressure hydrogen gas filled RF cavity was subjected to an intense proton beam to study the evolution of the beam induced plasma inside the cavity. The electron recombination rate with the dense ionized hydrogen plasma has been measured under varying conditions. Recombination rates as high as 10^-7 cm³/s have been recorded. This technique shows promise in the R&D program for a muon accelerator. The use of hydrogen, both as a way to prevent breakdown in an RF cavity and as a mechanism for cooling a beam of muons, will be discussed.

MOPPR070

Beam Profile Measurement in MTA Beam Line for High Pressure RF Cavity Beam Test

948

M.R. Jana, A.D. Bross, S. Geer, C. Johnstone, T. Kobilarcik, G.M. Koizumi, M.A. Leonova, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, K. Yonehara
Fermilab, Batavia, USA
M. Chung
Handong Global University, Pohang, Republic of Korea
M.G. Collura
Politecnico di Torino, Torino, Italy
B.T. Freemire, P.M. Hanlet, Y. Torun
IIT, Chicago, Illinois, USA

Funding: This work is supported by the United States Department of Energy under contract DE-AC02-07CH11359.
The recent High Pressure RF (HPRF) cavity experiment at the MuCool Test Area (MTA) used a 400 MeV Linac proton beam to study the beam loading effect. When the energetic proton beam passes through the cavity, it ionizes the inside gas and produces electrons. These electrons consume RF power inside the cavity. The number of electrons produced per cm inside the cavity (at 950 psi Hydrogen gas) per incident proton is 1200. The measurement of beam position and profile are necessary. The MTA is a flammable gas (Hydrogen) hazard zone, so we have developed a passive beam diagnostic instrument using a Chromox-6 scintillation screen and CCD camera. This paper presents quantitative information about beam position and beam profile. A neutral density filter was used to avoid saturation of the CCD camera. Image data is filtered and fitted with a Gaussian function to compute the beam size. The beam profile obtained from the scintillation screen will be compared with a multi-wire beam profile.

TUPPC044

Emittance and Phase Space Tomography for the Fermilab Linac

1263

C. Johnstone, F.G.G. Garcia, T. Kobilarcik, G.M. Koizumi, C.D. Moore, D.L. Newhart
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Dept. of Energy.
The Fermilab Linac delivers a variable intensity, 400-MeV beam to the The MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a de-convolution of the profile data. Preliminary measurements using this diagnostic section are reported here.