HB2012 - List of Keywords (pick-up)

Paper	Title	Other Keywords	Page
THO1B02	Test of Optical Stochastic Cooling in Fermilab	damping, radiation, kicker, optics	514
	V.A. Lebedev Fermilab, Batavia, USA M.S. Zolotorev LBNL, Berkeley, California, USA
	A new 150 MeV electron storage ring is planned to be build in Fermilab. The construction of new machine pursues two goals a test of highly non-linear integrable optics and a test of optical stochastic cooling (OSC). This paper discusses details of OSC arrangements and choice of major parameters of the cooling scheme. At the first step the cooling will be achieved without optical amplifier. It should introduce the damping rates of about 1 order of magnitudes higher than the cooling rates due to synchrotron radiation. Similar scheme looks as a promising technique for the LHC luminosity upgrade. Its details are also discussed.
	Slides THO1B02 [1.109 MB]

THO1B05	Broad-band Transverse Feedback against e-cloud or TMCI: Plan and Status	feedback, controls, kicker, electron	527
	C.H. Rivetta, J.M. Cesaratto, J.D. Fox, M.T.F. Pivi, O. Turgut, S. Uemura SLAC, Menlo Park, California, USA W. Höfle, K.S.B. Li CERN, Geneva, Switzerland
	The feedback control of intra-bunch instabilities driven by electron-clouds or strong head-tail coupling (Transverse mode coupled instabilities, TMCI) requires bandwidth sufficient to sense the vertical position and apply multiple corrections within a nanosecond-scale bunch. These requirements impose challenges and limits in the design and implementation of the feedback system. To develop the feedback control prototype, different research areas have been pursed to model and identify the bunch dynamics, design the feedback control and implement the GigaHertz bandwidth hardware. This paper presents those R&D lines and reports on the progress as it stands today. It presents preliminary results of feedback systems stabilizing the transverse intra-bunch motion, based on macro-particle simulation codes (CMAD / HeadTail) and measurement results of the beam motion when it is driven by particular excitation signals.
	Slides THO1B05 [7.197 MB]

THO3C02	Momentum Spread Determination of Linac Beams Using Incoherent Components of the Bunch Signals	cavity, linac, synchrotron, bunching	583
	P. Kowina, P. Forck, M. Schwickert GSI, Darmstadt, Germany F. Caspers CERN, Geneva, Switzerland
	Measurements of the momentum spread of the beam particles are of great importance when optimizing linac settings for high current operation with controlled longitudinal phase space occupation. A new method of momentum spread determination was tested at the GSI heavy ion linear accelerator UNILAC. The method is based on an analysis of incoherent components of the bunch signal. A significant enhancement of the signal-to-noise ratio was achieved by means of a resonant pick-up of pill-box shape. Spectra were analyzed on the 36th harmonics of the linac rf-frequency, i.e. at 1.3 GHz. Thus, the contribution of coherent components in the frequency spectrum of the bunched beam, e.g. due to common mode, was significantly damped. Fast digital processing and gating synchronized to the bunch train allowed for a drastic reduction of the measurement time and, additionally, suppressed noise signals in the frequency spectrum. This contribution describes the measurement setup and discusses first results obtained with heavy ion beams.
	Slides THO3C02 [2.131 MB]

THO3C06	On-line Calibration Schemes for RF-based Beam Diagnostics	resonance, target, proton, diagnostics	601
	P.-A. Duperrex, U. Müller PSI, Villigen PSI, Switzerland
	RF-based beam diagnostics such as BPMs and beam current monitors rely on precise RF signal measurements. Temperature drifts and differences in the overall measurement chain gain make such measurements very challenging and calibration validity over time is an issue. Over some years, on-line calibration schemes for BPMs and current monitors have been developed. These innovative schemes are based on the use of a pilot signal at a frequency offset from the measurement frequency. Results, advantages and disadvantages of such schemes are discussed.
	Slides THO3C06 [2.742 MB]

Paper

Title

Other Keywords

Page

THO1B02

Test of Optical Stochastic Cooling in Fermilab

damping, radiation, kicker, optics

514

V.A. Lebedev
Fermilab, Batavia, USA
M.S. Zolotorev
LBNL, Berkeley, California, USA

A new 150 MeV electron storage ring is planned to be build in Fermilab. The construction of new machine pursues two goals a test of highly non-linear integrable optics and a test of optical stochastic cooling (OSC). This paper discusses details of OSC arrangements and choice of major parameters of the cooling scheme. At the first step the cooling will be achieved without optical amplifier. It should introduce the damping rates of about 1 order of magnitudes higher than the cooling rates due to synchrotron radiation. Similar scheme looks as a promising technique for the LHC luminosity upgrade. Its details are also discussed.

Slides THO1B02 [1.109 MB]

THO1B05

Broad-band Transverse Feedback against e-cloud or TMCI: Plan and Status

feedback, controls, kicker, electron

527

C.H. Rivetta, J.M. Cesaratto, J.D. Fox, M.T.F. Pivi, O. Turgut, S. Uemura
SLAC, Menlo Park, California, USA
W. Höfle, K.S.B. Li
CERN, Geneva, Switzerland

The feedback control of intra-bunch instabilities driven by electron-clouds or strong head-tail coupling (Transverse mode coupled instabilities, TMCI) requires bandwidth sufficient to sense the vertical position and apply multiple corrections within a nanosecond-scale bunch. These requirements impose challenges and limits in the design and implementation of the feedback system. To develop the feedback control prototype, different research areas have been pursed to model and identify the bunch dynamics, design the feedback control and implement the GigaHertz bandwidth hardware. This paper presents those R&D lines and reports on the progress as it stands today. It presents preliminary results of feedback systems stabilizing the transverse intra-bunch motion, based on macro-particle simulation codes (CMAD / HeadTail) and measurement results of the beam motion when it is driven by particular excitation signals.

Slides THO1B05 [7.197 MB]

THO3C02

Momentum Spread Determination of Linac Beams Using Incoherent Components of the Bunch Signals

cavity, linac, synchrotron, bunching

583

P. Kowina, P. Forck, M. Schwickert
GSI, Darmstadt, Germany
F. Caspers
CERN, Geneva, Switzerland

Measurements of the momentum spread of the beam particles are of great importance when optimizing linac settings for high current operation with controlled longitudinal phase space occupation. A new method of momentum spread determination was tested at the GSI heavy ion linear accelerator UNILAC. The method is based on an analysis of incoherent components of the bunch signal. A significant enhancement of the signal-to-noise ratio was achieved by means of a resonant pick-up of pill-box shape. Spectra were analyzed on the 36th harmonics of the linac rf-frequency, i.e. at 1.3 GHz. Thus, the contribution of coherent components in the frequency spectrum of the bunched beam, e.g. due to common mode, was significantly damped. Fast digital processing and gating synchronized to the bunch train allowed for a drastic reduction of the measurement time and, additionally, suppressed noise signals in the frequency spectrum. This contribution describes the measurement setup and discusses first results obtained with heavy ion beams.

Slides THO3C02 [2.131 MB]

THO3C06

On-line Calibration Schemes for RF-based Beam Diagnostics

resonance, target, proton, diagnostics

601

P.-A. Duperrex, U. Müller
PSI, Villigen PSI, Switzerland

RF-based beam diagnostics such as BPMs and beam current monitors rely on precise RF signal measurements. Temperature drifts and differences in the overall measurement chain gain make such measurements very challenging and calibration validity over time is an issue. Over some years, on-line calibration schemes for BPMs and current monitors have been developed. These innovative schemes are based on the use of a pilot signal at a frequency offset from the measurement frequency. Results, advantages and disadvantages of such schemes are discussed.

Slides THO3C06 [2.742 MB]