PAC2013 - List of Authors (Torun, Y.)

Paper

Title

Page

High Pressure Gas-Filled RF Cavities for Use in a Muon Cooling Channel

419

B.T. Freemire, P.M. Hanlet, Y. Torun
IIT, Chicago, Illinois, USA
M. Chung, M.R. Jana, M.A. Leonova, A. Moretti, T.A. Schwarz, A.V. Tollestrup, Y. Torun, K. Yonehara
Fermilab, Batavia, USA
M.G. Collura
Politecnico di Torino, Torino, Italy
R.P. Johnson
Muons, Inc, Illinois, USA

A high pressure hydrogen gas-filled RF (HPRF) cavity can operate in the multi-Tesla magnetic fields required for a muon accelerator cooling channel. A beam test was performed at the Fermilab MuCool Test Area by sending a 400 MeV proton beam through an 805 MHz cavity and quantifying the effects of the resulting plasma within the cavity. The resulting energy loss per electron-ion pair produced has been measured at 10^-18 to 10^-16 J every RF cycle. Doping the hydrogen gas with oxygen greatly decreases the lifetime of an electron, thereby improving the performance of the HPRF cavity. Electron lifetimes as short as 1 ns have been measured. The recombination rate of positive and negative ions in the cavity has been measured on the order of 10^-8 cm³/s. Extrapolation in both gas pressure and beam intensity are required to obtain Muon Collider parameters, however the results indicate HPRF cavities can be used in a muon accelerator cooling channel.

Slides TUODA1 [12.191 MB]

WEPMA03

Tuner System Assembly and Tests for the 201-MHz MICE Cavity

987

L. Somaschini
INFN-Pisa, Pisa, Italy
A.J. DeMello, D. Li, S.P. Virostek
LBNL, Berkeley, California, USA
P.M. Hanlet
IIT, Chicago, Illinois, USA
A. Moretti, R.J. Pasquinelli, D.W. Peterson, Y. Torun
Fermilab, Batavia, USA

Funding: Supported by the US Department of Energy.
The MICE cavities include a mechanical tuning system consisting of stainless steel flexure forks attached to the cavity body and driven by pneumatic actuators. The first of these systems was assembled and tested at Fermilab for use at the MuCool Test Area. The actuators were calibrated on a test hoop. The cavity body was measured and the fork contact pads machined to fit. Actuators were mounted on the vacuum vessel housing the cavity. The transfer function of the tuning system was measured and frequency control software implemented.

THPMA08

Fermilab MuCool Test Area Cavity Conditioning Control Using LabVIEW

1370

D.W. Peterson, Y. Torun
Fermilab, Batavia, USA
Y. Torun
Illinois Institute of Technology, Chicago, IL, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.
Automated RF cavity conditioning controls have been implemented in the Fermilab MuCool Test Area using National Instruments LabVIEW. Display of RF paramaters, cavity gradient and diagnostic signals are provided for real-time monitoring. Oscilloscope traces and operating parameters are logged automatically. Gradient ramping and cavity breakdown detection allow unattended operation. Key parameters are made available to the Fermilab ACNET system for viewing by users.

WEPMA12

Investigation of Breakdown Induced Surface Damage on 805 MHz Pill Box Cavity Interior Surfaces

1007

M.R. Jana, M. Chung, M.A. Leonova, A. Moretti, A.V. Tollestrup, K. Yonehara
Fermilab, Batavia, USA
D.L. Bowring
LBNL, Berkeley, California, USA
G. Flanagan
Muons, Inc, Illinois, USA
B.T. Freemire, Y. Torun
IIT, Chicago, Illinois, USA

The MuCool Test Area (MTA) at Fermilab is a facility to develop the technology required for ionization cooling for a future Muon Collider and/or Neutrino Factory. As part of this research program, we have tested an 805 MHz Pill Box RF cavity in multi-Tesla magnetic field to study the effects of the static magnetic field on the cavity operation. This study gives useful information on field emitters in the cavity, dark current, surface conditioning, breakdown mechanism and material properties of the cavity. All these factors determine the maximum accelerating gradient in the cavity. This paper discusses the image processing technique for the quantitative estimation of spark damage spot distribution on the Pill Box RF cavity interior surfaces. The distribution is compared with the electric field distribution predicted by computer code calculation. The local spark density is proportional to probability of surface breakdown and shows a power law dependence on the maximum electric field (E). This E dependence is consistent with dark current calculated from Fowler-Nordheim equation.

THPHO18

Status of the Muon Ionization Cooling Experiment (MICE)

1340

Y. Torun
IIT, Chicago, Illinois, USA
M.S. Zisman
LBNL, Berkeley, California, USA

Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231.
A muon collider and a muon-based neutrino factory are attractive options for particle physics. Their optimal realization requires demonstration of muon ionization cooling, a technique to rapidly reduce the emittance of the tertiary muon beam. MICE, performed by a team from the U.S., Europe, and Asia and sited at Rutherford Appleton Laboratory, will provide this demonstration. The experiment comprises one cell of a representative cooling channel, bracketed upstream and downstream by spectrometer solenoid magnets containing scintillating fiber tracking detectors. Characterization of the ISIS muon beam line is complete. Fabrication of the superconducting spectrometer solenoids is nearly complete, with one having passed its acceptance tests, and the second nearly ready for testing. The first focus coil is presently being tested, with a second unit ready shortly. A prototype coil for the 1.5-m-diameter coupling coil is also being tested, and its cryostat is ready for fabrication. Other required hardware, including RF cavities and liquid-H absorbers, is also fabricated. The status of the major hardware items and plans for carrying out the experiment are described.

WEPMA16

Assembly and Testing of the First 201-MHz MICE Cavity at Fermilab

1016

Y. Torun
Illinois Institute of Technology, Chicago, IL, USA
D.L. Bowring, A.J. DeMello, D. Li, T.H. Luo, S.P. Virostek
LBNL, Berkeley, California, USA
P.M. Hanlet
IIT, Chicago, Illinois, USA
M.A. Leonova, A. Moretti, R.J. Pasquinelli, D.W. Peterson, R.P. Schultz, J.T. Volk
Fermilab, Batavia, USA
T.H. Luo
UMiss, University, Mississippi, USA
L. Somaschini
INFN-Pisa, Pisa, Italy

Funding: Supported by the US Department of Energy.
The International Muon Ionization Cooling Experiment (MICE) includes two linear accelerator sections with four RF cavities each within a shared vacuum vessel. Ten cavity bodies have been fabricated for MICE including two spares and one was electropolished. A special vacuum vessel was built to house this cavity and form the 201-MHz Single-Cavity Module. The module was assembled, instrumented and tested at Fermilab for installation and operation in the MuCool Test Area.

THPMA08

Fermilab MuCool Test Area Cavity Conditioning Control Using LabVIEW

1370

D.W. Peterson, Y. Torun
Fermilab, Batavia, USA
Y. Torun
Illinois Institute of Technology, Chicago, IL, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.
Automated RF cavity conditioning controls have been implemented in the Fermilab MuCool Test Area using National Instruments LabVIEW. Display of RF paramaters, cavity gradient and diagnostic signals are provided for real-time monitoring. Oscilloscope traces and operating parameters are logged automatically. Gradient ramping and cavity breakdown detection allow unattended operation. Key parameters are made available to the Fermilab ACNET system for viewing by users.

Paper	Title	Page
TUODA1	High Pressure Gas-Filled RF Cavities for Use in a Muon Cooling Channel	419
	B.T. Freemire, P.M. Hanlet, Y. Torun IIT, Chicago, Illinois, USA M. Chung, M.R. Jana, M.A. Leonova, A. Moretti, T.A. Schwarz, A.V. Tollestrup, Y. Torun, K. Yonehara Fermilab, Batavia, USA M.G. Collura Politecnico di Torino, Torino, Italy R.P. Johnson Muons, Inc, Illinois, USA
	A high pressure hydrogen gas-filled RF (HPRF) cavity can operate in the multi-Tesla magnetic fields required for a muon accelerator cooling channel. A beam test was performed at the Fermilab MuCool Test Area by sending a 400 MeV proton beam through an 805 MHz cavity and quantifying the effects of the resulting plasma within the cavity. The resulting energy loss per electron-ion pair produced has been measured at 10^-18 to 10^-16 J every RF cycle. Doping the hydrogen gas with oxygen greatly decreases the lifetime of an electron, thereby improving the performance of the HPRF cavity. Electron lifetimes as short as 1 ns have been measured. The recombination rate of positive and negative ions in the cavity has been measured on the order of 10^-8 cm³/s. Extrapolation in both gas pressure and beam intensity are required to obtain Muon Collider parameters, however the results indicate HPRF cavities can be used in a muon accelerator cooling channel.
	Slides TUODA1 [12.191 MB]

WEPMA03	Tuner System Assembly and Tests for the 201-MHz MICE Cavity	987
	L. Somaschini INFN-Pisa, Pisa, Italy A.J. DeMello, D. Li, S.P. Virostek LBNL, Berkeley, California, USA P.M. Hanlet IIT, Chicago, Illinois, USA A. Moretti, R.J. Pasquinelli, D.W. Peterson, Y. Torun Fermilab, Batavia, USA
	Funding: Supported by the US Department of Energy. The MICE cavities include a mechanical tuning system consisting of stainless steel flexure forks attached to the cavity body and driven by pneumatic actuators. The first of these systems was assembled and tested at Fermilab for use at the MuCool Test Area. The actuators were calibrated on a test hoop. The cavity body was measured and the fork contact pads machined to fit. Actuators were mounted on the vacuum vessel housing the cavity. The transfer function of the tuning system was measured and frequency control software implemented.

THPMA08	Fermilab MuCool Test Area Cavity Conditioning Control Using LabVIEW	1370
	D.W. Peterson, Y. Torun Fermilab, Batavia, USA Y. Torun Illinois Institute of Technology, Chicago, IL, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy. Automated RF cavity conditioning controls have been implemented in the Fermilab MuCool Test Area using National Instruments LabVIEW. Display of RF paramaters, cavity gradient and diagnostic signals are provided for real-time monitoring. Oscilloscope traces and operating parameters are logged automatically. Gradient ramping and cavity breakdown detection allow unattended operation. Key parameters are made available to the Fermilab ACNET system for viewing by users.

WEPMA12	Investigation of Breakdown Induced Surface Damage on 805 MHz Pill Box Cavity Interior Surfaces	1007
	M.R. Jana, M. Chung, M.A. Leonova, A. Moretti, A.V. Tollestrup, K. Yonehara Fermilab, Batavia, USA D.L. Bowring LBNL, Berkeley, California, USA G. Flanagan Muons, Inc, Illinois, USA B.T. Freemire, Y. Torun IIT, Chicago, Illinois, USA
	The MuCool Test Area (MTA) at Fermilab is a facility to develop the technology required for ionization cooling for a future Muon Collider and/or Neutrino Factory. As part of this research program, we have tested an 805 MHz Pill Box RF cavity in multi-Tesla magnetic field to study the effects of the static magnetic field on the cavity operation. This study gives useful information on field emitters in the cavity, dark current, surface conditioning, breakdown mechanism and material properties of the cavity. All these factors determine the maximum accelerating gradient in the cavity. This paper discusses the image processing technique for the quantitative estimation of spark damage spot distribution on the Pill Box RF cavity interior surfaces. The distribution is compared with the electric field distribution predicted by computer code calculation. The local spark density is proportional to probability of surface breakdown and shows a power law dependence on the maximum electric field (E). This E dependence is consistent with dark current calculated from Fowler-Nordheim equation.

THPHO18	Status of the Muon Ionization Cooling Experiment (MICE)	1340
	Y. Torun IIT, Chicago, Illinois, USA M.S. Zisman LBNL, Berkeley, California, USA
	Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231. A muon collider and a muon-based neutrino factory are attractive options for particle physics. Their optimal realization requires demonstration of muon ionization cooling, a technique to rapidly reduce the emittance of the tertiary muon beam. MICE, performed by a team from the U.S., Europe, and Asia and sited at Rutherford Appleton Laboratory, will provide this demonstration. The experiment comprises one cell of a representative cooling channel, bracketed upstream and downstream by spectrometer solenoid magnets containing scintillating fiber tracking detectors. Characterization of the ISIS muon beam line is complete. Fabrication of the superconducting spectrometer solenoids is nearly complete, with one having passed its acceptance tests, and the second nearly ready for testing. The first focus coil is presently being tested, with a second unit ready shortly. A prototype coil for the 1.5-m-diameter coupling coil is also being tested, and its cryostat is ready for fabrication. Other required hardware, including RF cavities and liquid-H absorbers, is also fabricated. The status of the major hardware items and plans for carrying out the experiment are described.

WEPMA16	Assembly and Testing of the First 201-MHz MICE Cavity at Fermilab	1016
	Y. Torun Illinois Institute of Technology, Chicago, IL, USA D.L. Bowring, A.J. DeMello, D. Li, T.H. Luo, S.P. Virostek LBNL, Berkeley, California, USA P.M. Hanlet IIT, Chicago, Illinois, USA M.A. Leonova, A. Moretti, R.J. Pasquinelli, D.W. Peterson, R.P. Schultz, J.T. Volk Fermilab, Batavia, USA T.H. Luo UMiss, University, Mississippi, USA L. Somaschini INFN-Pisa, Pisa, Italy
	Funding: Supported by the US Department of Energy. The International Muon Ionization Cooling Experiment (MICE) includes two linear accelerator sections with four RF cavities each within a shared vacuum vessel. Ten cavity bodies have been fabricated for MICE including two spares and one was electropolished. A special vacuum vessel was built to house this cavity and form the 201-MHz Single-Cavity Module. The module was assembled, instrumented and tested at Fermilab for installation and operation in the MuCool Test Area.

THPMA08	Fermilab MuCool Test Area Cavity Conditioning Control Using LabVIEW	1370
	D.W. Peterson, Y. Torun Fermilab, Batavia, USA Y. Torun Illinois Institute of Technology, Chicago, IL, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy. Automated RF cavity conditioning controls have been implemented in the Fermilab MuCool Test Area using National Instruments LabVIEW. Display of RF paramaters, cavity gradient and diagnostic signals are provided for real-time monitoring. Oscilloscope traces and operating parameters are logged automatically. Gradient ramping and cavity breakdown detection allow unattended operation. Key parameters are made available to the Fermilab ACNET system for viewing by users.