COOL2015 - List of Authors (Summers, D.J.)

Paper	Title	Page
MOPF01	Final Cooling for a High Energy High Luminosity Collider
	D.V. Neuffer Fermilab, Batavia, Illinois, USA T.L. Hart, D.J. Summers UMiss, University, Mississippi, USA
	The final cooling system for a high-energy high-luminosity muon collider requires reduction of the transverse emittance by an order of magnitude to ~0.00003 m (rms, N), while allowing longitudinal emittance increase to ~0.1m. In an initial approach, this is obtained by transverse cooling of low-energy muons within a sequence of high field solenoids with low-frequency rf systems. Since the final cooling steps are actually emittance exchange, much of this transformation can be obtained by thick wedge absorbers at matched parameters. Other variations using quad-based cooling channels, transverse beam slicing and round to flat transforms can be used. in x-y, with transverse slicing and longitudinal recombination are discussed. Development of lowest emittance cooling with final exchange is discussed.
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MOPF07	Final Muon Ionization Cooling Channel using Quadrupole Doublets for Strong Focusing	43
	J.G. Acosta, L.M. Cremaldi, T.L. Hart, S.J. Oliveros, D.J. Summers UMiss, University, Mississippi, USA D.V. Neuffer Fermilab, Batavia, Illinois, USA
	Considerable progress has been made in the design of muon ionization cooling for a collider. A 6D normalized emittance of 0.123 cubic mm has been achieved in simulation, almost a factor of a million in cooling. However, the 6D emittance required by a high luminosity muon collider is 0.044 cubic mm. We explore a final cooling channel composed of quadrupole doublets limited to 14 Tesla. Flat beams formed by a skew quadrupole triplet are used. The low beta regions, as low as 5 mm, produced by the strong focusing quadrupoles are occupied by dense, low Z absorbers that cool the beam. Work is in progress to keep muons with different path lengths in phase with the RF located between cells and to modestly enlarge quadrupole admittance. Calculations and individual cell simulations indicate that the final cooling needed may be possible. Full simulations are in progress. After cooling, emittance exchange in vacuum reduces the transverse emittance to 25 microns and lets the longitudinal emittance grow to 70 mm as needed by a collider. Septa slices a bunch into 17 parts. RF deflector cavities, as used in CLIC tests, form a 3.7 meter long bunch train. Snap bunch coalescence combines the 17 bunches into one in a 21 GeV ring in 55 microseconds.
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TUPF01	Cooling for a High Luminosity 100 TeV Proton Antiproton Collider	97
	S.J. Oliveros, J.G. Acosta, L.M. Cremaldi, D.J. Summers UMiss, University, Mississippi, USA
	A 10³⁴ luminosity 100 TeV proton-antiproton collider is explored. The cross section for many high mass states is 10x higher in p-pbar than p-p collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the vacuum system, because lower beam currents can produce the same rare event rates. Events are also more central, allowing a shorter detector with less space between quadrupole triplets and a smaller beta twiss for higher luminosity. To keep up with the antiproton burn rate, a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12x. At Fermilab, antiprotons were stochastically cooled in one debuncher and one accumulator ring. Because the stochastic cooling time scales as the number of particles, 12 independent cooling systems would be used, each one with one debuncher/momentum equalizer ring and two accumulator rings. One electron cooling ring would follow the stochastic cooling rings. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and longitudinal synchrotron damping.
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Paper

Title

Page

MOPF01

Final Cooling for a High Energy High Luminosity Collider

D.V. Neuffer
Fermilab, Batavia, Illinois, USA
T.L. Hart, D.J. Summers
UMiss, University, Mississippi, USA

The final cooling system for a high-energy high-luminosity muon collider requires reduction of the transverse emittance by an order of magnitude to ~0.00003 m (rms, N), while allowing longitudinal emittance increase to ~0.1m. In an initial approach, this is obtained by transverse cooling of low-energy muons within a sequence of high field solenoids with low-frequency rf systems. Since the final cooling steps are actually emittance exchange, much of this transformation can be obtained by thick wedge absorbers at matched parameters. Other variations using quad-based cooling channels, transverse beam slicing and round to flat transforms can be used. in x-y, with transverse slicing and longitudinal recombination are discussed. Development of lowest emittance cooling with final exchange is discussed.

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MOPF07

Final Muon Ionization Cooling Channel using Quadrupole Doublets for Strong Focusing

43

J.G. Acosta, L.M. Cremaldi, T.L. Hart, S.J. Oliveros, D.J. Summers
UMiss, University, Mississippi, USA
D.V. Neuffer
Fermilab, Batavia, Illinois, USA

Considerable progress has been made in the design of muon ionization cooling for a collider. A 6D normalized emittance of 0.123 cubic mm has been achieved in simulation, almost a factor of a million in cooling. However, the 6D emittance required by a high luminosity muon collider is 0.044 cubic mm. We explore a final cooling channel composed of quadrupole doublets limited to 14 Tesla. Flat beams formed by a skew quadrupole triplet are used. The low beta regions, as low as 5 mm, produced by the strong focusing quadrupoles are occupied by dense, low Z absorbers that cool the beam. Work is in progress to keep muons with different path lengths in phase with the RF located between cells and to modestly enlarge quadrupole admittance. Calculations and individual cell simulations indicate that the final cooling needed may be possible. Full simulations are in progress. After cooling, emittance exchange in vacuum reduces the transverse emittance to 25 microns and lets the longitudinal emittance grow to 70 mm as needed by a collider. Septa slices a bunch into 17 parts. RF deflector cavities, as used in CLIC tests, form a 3.7 meter long bunch train. Snap bunch coalescence combines the 17 bunches into one in a 21 GeV ring in 55 microseconds.

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TUPF01

Cooling for a High Luminosity 100 TeV Proton Antiproton Collider

97

S.J. Oliveros, J.G. Acosta, L.M. Cremaldi, D.J. Summers
UMiss, University, Mississippi, USA

A 10³⁴ luminosity 100 TeV proton-antiproton collider is explored. The cross section for many high mass states is 10x higher in p-pbar than p-p collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the vacuum system, because lower beam currents can produce the same rare event rates. Events are also more central, allowing a shorter detector with less space between quadrupole triplets and a smaller beta twiss for higher luminosity. To keep up with the antiproton burn rate, a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12x. At Fermilab, antiprotons were stochastically cooled in one debuncher and one accumulator ring. Because the stochastic cooling time scales as the number of particles, 12 independent cooling systems would be used, each one with one debuncher/momentum equalizer ring and two accumulator rings. One electron cooling ring would follow the stochastic cooling rings. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and longitudinal synchrotron damping.

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