2011 Particle Accelerator Conference - List of Authors (Blednykh, A.)

Paper	Title	Page
MOP192	NSLS-II BPM System Protection from Rogue Mode Coupling	450
	A. Blednykh, B. Bacha, A. Borrelli, M.J. Ferreira, C. Hetzel, H.-C. Hseuh, B.N. Kosciuk, S. Krinsky, O. Singh, K. Vetter BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract DE-AC02-98CH10886 Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.

MOP205	NSLS-II Injection Straight Diagnostics	477
	I. Pinayev, A. Blednykh, M.J. Ferreira, R.P. Fliller, B.N. Kosciuk, T.V. Shaftan, G.M. Wang BNL, Upton, Long Island, New York, USA
	The ultra-bright light source being developed by the NSLS-II project will utilize top-up injection and fine tuning of the injection process is mandatory. In the paper we present the diagnostics installed on the injection straight. Its usage for commissioning and tuning of the injection cycle is also described.

MOP266	Stripline Kicker Design for NSLS2 Storage Ring	603
	W.X. Cheng, A. Blednykh, S. Krinsky, O. Singh BNL, Upton, Long Island, New York, USA
	In the NSLS2 storage ring, there are four stripline kickers/pickups. Two long striplines with electrode length of 30cm will be used as bunch-by-bunch transverse feedback actuators. Two short stripline kickers/pickups with 15cm length will mainly used for tune measurement excitation or signal pickup for the beam stability monitor. High shunt impedance of the long stripline kickers is demanded to produce 200μs damping time. Meanwhile the beam impedance should be minimized. The design work for these two types of stripline is discussed in this paper.

TUP227	Status of NSLS-II Storage Ring Vacuum Systems	1244
	H.-C. Hseuh, A. Blednykh, L. Doom, M.J. Ferreira, C. Hetzel, J. Hu, S. Leng, C. Longo, V. Ravindranath, K. Roy, S.K. Sharma, F.J. Willeke, K. Wilson, D. Zigrosser BNL, Upton, Long Island, New York, USA
	Funding: Work performed under the auspices of U.S. Department of Energy, under contract DE-AC02-98CH10886 National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3- GeV, high-flux and high-brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system has extruded aluminium chambers, with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers are used to intercept the un-used bending magnet radiation. In-situ bakeout is implemented to achieve fast conditioning during initial commissioning and after interventions.

WEP176	Loss Factor of Tapered Structures for Short Bunches	1816
	A. Blednykh, S. Krinsky BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract DE-AC02-98CH10886 Using the electromagnetic simulation code ECHO, we have found* a simple phenomenological formula that accurately describes the loss factor for short bunches traversing an axisymmetric tapered collimator. In this paper, we consider tapered collimators with elliptical cross-section and use the GdfidL code to calculate the loss factor dependence on the geometric parameters for short bunches. The results for both axisymmetric and elliptical collimators are discussed. * A. Blednykh and S. Krinsky, Phys. Rev. ST-AB 13, 064401 (2010).

WEP178	Electromagnetic Field Measurement of Fundamental and Higher-order Modes for 7-cell Cavity of PETRA-II	1822
	Y. Kawashima, A. Blednykh, J. Cupolo, M.A. Davidsaver, B. Holub, H. Ma, J. Oliva, J. Rose, R. Sikora, M. Yeddulla BNL, Upton, Long Island, New York, USA
	The booster synchrotron for NSLS-II will include a 7-cell PETRA cavity, which was manufactured for the PETRA-II project at DESY. The cavity fundamental frequency operates at 500 MHz. In order to verify the impedances of the fundamental and higher-order modes (HOM) which were calculated by computer code, we measured the magnitude of the electromagnetic field of the fundamental acceleration mode and HOM’s, using the bead-pull method. To keep the cavity body temperature constant, we used a chiller system to supply cooling water at 20 degrees C. The bead-pull measurement was automated with a computer. We encountered some issues during the measurement process due to the difficulty in measuring the electromagnetic field magnitude in a multi-cell cavity as compared to a single-cell cavity. We describe the apparatus for the field measurement and the obtained results.

THP136	Short Pulse Generation by Laser Slicing at NSLSII	2381
	L.-H. Yu, A. Blednykh, O.V. Chubar, W. Guo, S. Krinsky, Y. Li, T.V. Shaftan, G.M. Wang, F.J. Willeke, L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract DE-AC02-98CH10886. We propose an upgrade R&D project for NSLSII to generate sub-pico-second short x-ray pulses using laser slicing. In this paper we discuss the basic parameters for this system and present a specific example for a viable design and its performance. Since the installation of the laser slicing system into the storage ring will break the symmetry of the lattice, we demonstrate it is possible to recover the dynamical aperture to the original design goal of the ring.

THP193	Study of Single and Coupled-Bunch Instabilities for NSLS-II	2483
	G. Bassi, A. Blednykh BNL, Upton, Long Island, New York, USA
	We study single and coupled-bunch instabilities for the NSLS-II storage ring with a recently developed parallel tracking code. For accurate modelling of the coupled-bunch instability, we investigate improvements to current point-bunch models to take into account finite bunch-size effects.

THP216	Progress with NSLS-II Injection Straight Section Design	2528
	T.V. Shaftan, A. Blednykh, W.R. Casey, L.R. Dalesio, R. Faussete, M.J. Ferreira, R.P. Fliller, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, E.D. Johnson, B.N. Kosciuk, S. Kowalski, S.L. Kramer, D. Padrazo, B. Parker, I. Pinayev, S.K. Sharma, O. Singh, C.J. Spataro, G.M. Wang, F.J. Willeke BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by U.S. DOE, Contract No.DE-AC02-98CH10886 NSLS-II injection straight section consists of the pulsed and DC/Slow bumps, septa system, beam trajectory correction and diagnostics systems. In this paper we discuss overall injection straight layout, preliminary element designs, specifications for the pulsed and DC magnets and their power supplies, vacuum devices and chambers and diagnostics devices.

Paper

Title

Page

NSLS-II BPM System Protection from Rogue Mode Coupling

450

A. Blednykh, B. Bacha, A. Borrelli, M.J. Ferreira, C. Hetzel, H.-C. Hseuh, B.N. Kosciuk, S. Krinsky, O. Singh, K. Vetter
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract DE-AC02-98CH10886
Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.

MOP205

NSLS-II Injection Straight Diagnostics

477

I. Pinayev, A. Blednykh, M.J. Ferreira, R.P. Fliller, B.N. Kosciuk, T.V. Shaftan, G.M. Wang
BNL, Upton, Long Island, New York, USA

The ultra-bright light source being developed by the NSLS-II project will utilize top-up injection and fine tuning of the injection process is mandatory. In the paper we present the diagnostics installed on the injection straight. Its usage for commissioning and tuning of the injection cycle is also described.

MOP266

Stripline Kicker Design for NSLS2 Storage Ring

603

W.X. Cheng, A. Blednykh, S. Krinsky, O. Singh
BNL, Upton, Long Island, New York, USA

In the NSLS2 storage ring, there are four stripline kickers/pickups. Two long striplines with electrode length of 30cm will be used as bunch-by-bunch transverse feedback actuators. Two short stripline kickers/pickups with 15cm length will mainly used for tune measurement excitation or signal pickup for the beam stability monitor. High shunt impedance of the long stripline kickers is demanded to produce 200μs damping time. Meanwhile the beam impedance should be minimized. The design work for these two types of stripline is discussed in this paper.

TUP227

Status of NSLS-II Storage Ring Vacuum Systems

1244

H.-C. Hseuh, A. Blednykh, L. Doom, M.J. Ferreira, C. Hetzel, J. Hu, S. Leng, C. Longo, V. Ravindranath, K. Roy, S.K. Sharma, F.J. Willeke, K. Wilson, D. Zigrosser
BNL, Upton, Long Island, New York, USA

Funding: Work performed under the auspices of U.S. Department of Energy, under contract DE-AC02-98CH10886
National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3- GeV, high-flux and high-brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system has extruded aluminium chambers, with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers are used to intercept the un-used bending magnet radiation. In-situ bakeout is implemented to achieve fast conditioning during initial commissioning and after interventions.

WEP176

Loss Factor of Tapered Structures for Short Bunches

1816

A. Blednykh, S. Krinsky
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract DE-AC02-98CH10886
Using the electromagnetic simulation code ECHO, we have found* a simple phenomenological formula that accurately describes the loss factor for short bunches traversing an axisymmetric tapered collimator. In this paper, we consider tapered collimators with elliptical cross-section and use the GdfidL code to calculate the loss factor dependence on the geometric parameters for short bunches. The results for both axisymmetric and elliptical collimators are discussed.
* A. Blednykh and S. Krinsky, Phys. Rev. ST-AB 13, 064401 (2010).

WEP178

Electromagnetic Field Measurement of Fundamental and Higher-order Modes for 7-cell Cavity of PETRA-II

1822

Y. Kawashima, A. Blednykh, J. Cupolo, M.A. Davidsaver, B. Holub, H. Ma, J. Oliva, J. Rose, R. Sikora, M. Yeddulla
BNL, Upton, Long Island, New York, USA

The booster synchrotron for NSLS-II will include a 7-cell PETRA cavity, which was manufactured for the PETRA-II project at DESY. The cavity fundamental frequency operates at 500 MHz. In order to verify the impedances of the fundamental and higher-order modes (HOM) which were calculated by computer code, we measured the magnitude of the electromagnetic field of the fundamental acceleration mode and HOM’s, using the bead-pull method. To keep the cavity body temperature constant, we used a chiller system to supply cooling water at 20 degrees C. The bead-pull measurement was automated with a computer. We encountered some issues during the measurement process due to the difficulty in measuring the electromagnetic field magnitude in a multi-cell cavity as compared to a single-cell cavity. We describe the apparatus for the field measurement and the obtained results.

THP136

Short Pulse Generation by Laser Slicing at NSLSII

2381

L.-H. Yu, A. Blednykh, O.V. Chubar, W. Guo, S. Krinsky, Y. Li, T.V. Shaftan, G.M. Wang, F.J. Willeke, L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract DE-AC02-98CH10886.
We propose an upgrade R&D project for NSLSII to generate sub-pico-second short x-ray pulses using laser slicing. In this paper we discuss the basic parameters for this system and present a specific example for a viable design and its performance. Since the installation of the laser slicing system into the storage ring will break the symmetry of the lattice, we demonstrate it is possible to recover the dynamical aperture to the original design goal of the ring.

THP193

Study of Single and Coupled-Bunch Instabilities for NSLS-II

2483

G. Bassi, A. Blednykh
BNL, Upton, Long Island, New York, USA

We study single and coupled-bunch instabilities for the NSLS-II storage ring with a recently developed parallel tracking code. For accurate modelling of the coupled-bunch instability, we investigate improvements to current point-bunch models to take into account finite bunch-size effects.

THP216

Progress with NSLS-II Injection Straight Section Design

2528

T.V. Shaftan, A. Blednykh, W.R. Casey, L.R. Dalesio, R. Faussete, M.J. Ferreira, R.P. Fliller, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, E.D. Johnson, B.N. Kosciuk, S. Kowalski, S.L. Kramer, D. Padrazo, B. Parker, I. Pinayev, S.K. Sharma, O. Singh, C.J. Spataro, G.M. Wang, F.J. Willeke
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by U.S. DOE, Contract No.DE-AC02-98CH10886
NSLS-II injection straight section consists of the pulsed and DC/Slow bumps, septa system, beam trajectory correction and diagnostics systems. In this paper we discuss overall injection straight layout, preliminary element designs, specifications for the pulsed and DC magnets and their power supplies, vacuum devices and chambers and diagnostics devices.