IBIC2014 - List of Authors (Crisp, J.L.)

Paper	Title	Page
TUPF16	FRIB Beam Position Monitor Pick-Up Design	355
	O. Yair, J.L. Crisp, G. Kiupel, S.M. Lidia, R.C. Webber FRIB, East Lansing, Michigan, USA
	Due to the different beam diameters and the inclusion of superconducting cavities, different Beam Position Monitor (BPM) types with welded buttons are to be used in the Facility for Rare Isotope Beams (FRIB). The varying BPM sizes include the following apertures: 40 mm, 50 mm, 100 mm, and 150 mm. The 40 mm BPMs include both warm and cold types where the cold BPMs are located in cryomodules next to SRF cavities. Steel-jacketed SiO2 coaxial cables with sealed SMA connectors have been selected as signal cables in the cryomodule insulating vacuum. These will connect to the BPM assembly at roughly 4 K temperature at one end and to the feedthrough flange in the vacuum vessel wall at 300 K at the other end. The 40 mm and 50 mm BPMs will include 20 mm custom-made buttons. The 100 mm and 150 mm aperture BPM buttons will be larger, anywhere from 30 mm to 40 mm. This paper will specify the mechanical and electrical design challenges and the resolutions associated with FRIB operations in the following areas: varying BPM conditions, changes in apertures, and variants in button sizes.
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPD21	AC Coupling Studies and Circuit Model for Loss Monitor Ring	455
	Z. Liu, J.L. Crisp, S.M. Lidia FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University. As a follow-up study to the initial design of FRIB Loss Monitor Ring (previously named Halo Monitor Ring [1]), we present recent results of coupling studies between the FRIB CW beam and the Loss Monitor Ring (LMR). While a ~33 kHz low-pass filter was proposed to attenuate high-frequency AC-coupled signals [1,2], the LMR current signal may still contain low frequency signals induced by the un-intercepted beam, for example, by the 50μs beam notch that repeats every 10ms. We use CST Microwave Studio to simulate the AC response of a Gaussian source signal and benchmarked it to analytical model. A circuit model for beam-notch-induced AC signal is deduced and should put a ~33pA (peak) bipolar pulse on the LMR at 100Hz repetition rate. Although its amplitude falls into our tolerable region, we could consider an extended background integration to eliminate this effect.
	Poster TUPD21 [1.201 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

Paper

Title

Page

FRIB Beam Position Monitor Pick-Up Design

355

O. Yair, J.L. Crisp, G. Kiupel, S.M. Lidia, R.C. Webber
FRIB, East Lansing, Michigan, USA

Due to the different beam diameters and the inclusion of superconducting cavities, different Beam Position Monitor (BPM) types with welded buttons are to be used in the Facility for Rare Isotope Beams (FRIB). The varying BPM sizes include the following apertures: 40 mm, 50 mm, 100 mm, and 150 mm. The 40 mm BPMs include both warm and cold types where the cold BPMs are located in cryomodules next to SRF cavities. Steel-jacketed SiO2 coaxial cables with sealed SMA connectors have been selected as signal cables in the cryomodule insulating vacuum. These will connect to the BPM assembly at roughly 4 K temperature at one end and to the feedthrough flange in the vacuum vessel wall at 300 K at the other end. The 40 mm and 50 mm BPMs will include 20 mm custom-made buttons. The 100 mm and 150 mm aperture BPM buttons will be larger, anywhere from 30 mm to 40 mm. This paper will specify the mechanical and electrical design challenges and the resolutions associated with FRIB operations in the following areas: varying BPM conditions, changes in apertures, and variants in button sizes.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPD21

AC Coupling Studies and Circuit Model for Loss Monitor Ring

455

Z. Liu, J.L. Crisp, S.M. Lidia
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
As a follow-up study to the initial design of FRIB Loss Monitor Ring (previously named Halo Monitor Ring [1]), we present recent results of coupling studies between the FRIB CW beam and the Loss Monitor Ring (LMR). While a ~33 kHz low-pass filter was proposed to attenuate high-frequency AC-coupled signals [1,2], the LMR current signal may still contain low frequency signals induced by the un-intercepted beam, for example, by the 50μs beam notch that repeats every 10ms. We use CST Microwave Studio to simulate the AC response of a Gaussian source signal and benchmarked it to analytical model. A circuit model for beam-notch-induced AC signal is deduced and should put a ~33pA (peak) bipolar pulse on the LMR at 100Hz repetition rate. Although its amplitude falls into our tolerable region, we could consider an extended background integration to eliminate this effect.

Poster TUPD21 [1.201 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)