Q. Kerns

Fermi National Accelerator Laboratory

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Papers

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Research Trends

Author Order

Document Type

Co-Authors

Harold W. Miller

Phoenix (United States)

C. Kerns

Fermi National Accelerator Laboratory

O. Fackler

German Center for Infection Research

D. Theriot

Fermi National Accelerator Laboratory

A. Bodek

University of Rochester

K.A. Jenkins

IBM Research - Thomas J. Watson Research Center

Y. Fukushima

High Energy Accelerator Research Organization

S. Segler

Fermi National Accelerator Laboratory

D. Yovanovitch

Children's Defense Fund

W. Marsh

Fermi National Accelerator Laboratory

Cooperative Institutions

Fermi National Accelerator Laboratory

123

Fermi Research Alliance

Lawrence Berkeley National Laboratory

University of California, Berkeley

Universities Research Association

SLAC National Accelerator Laboratory

California Institute of Technology

Brookhaven National Laboratory

Intelligent Fusion Technology (United States)

PRG S&Tech (South Korea)

Author Statistics

Papers

Citation

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i-10 index

Research Field

A critical survey of stretched-wire impedance measurements at Fermilab

P. Colestock P.J. Chou B. Fellenz M. Foley F.A. Harfoush

Bench measurements of the impedance of various beam line components as well as several test structures have been carried out using cavity perturbation and stretched wire methods. Several pitfalls of the wire measurement technique have been uncovered and improvements were developed to resolve ambiguities and improve overall accuracy. The authors summarize the results of their findings concerning measurement techniques, accuracy limitations, and the comparison with numerical simulation of model test structures.< >

Fermilab

Test bench

10.1109/pac.1991.164763

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Citations (1)

PERFORMANCE OF LllTON 805MHz, 12MW KLYSTRONS

Q. Kerns C. Kerns A. Moretti

The Fermilab Linac Upgrade[l] will increase the energy of the H linac from 201 to 401.5 MeV. This will be achieved by replacing the last four 201.24 MHz drift-tube linac cavities with seven 805 MHz side-coupled cavity modules. Each accelerator module will be powered with a 12 MW klystron-based power supply. The purpose of this report is to present a body of representative data for the klystron tubes at various conditions and to detail the procedures used.

Klystron

Fermilab

Upgrade

Drift tube

Source

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Citations (0)

Transductors for Current Sensing in the Dipole and Quadrupole Magnet Circuits of the Fermilab Main Ring

IEEE Transactions on Nuclear Science (1975)

Q. Kerns

Transductors are used as current measuring devices in the main accelerator quadrupole power supply feedback loop and as monitors in the dipole circuit. The development of these transductors is described, starting with the basic series - connected (Kraemer) transductor circuit, and adding the features of biasing and a voltage follower to obtain improved linearity and high slewing rate.

Biasing

Linearity

Quadrupole magnet

Fermilab

10.1109/tns.1975.4327865

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Citations (1)

RECENT RESULTS ON TOTAL NEUTRINO AND ANTINEUTRINO CROSS SECTIONS BY THE CFRR COLLABORATION

Presented at (1981)

B. C. Barish D. Novikoff Y. Fukushima M.H. Shaevitz P. A. Rapidis

Normalized cross sections for charged current neutrino and antineutrino-nucleon scattering are presented. The cross sections can be parametrized as a linear rising function of the incident neutrino energy, with sigma/sub ..nu..//E = 0.720 +- 0.030 x 10/sup -38/ and sigma/sub anti ..nu..//E = 0.360 +- 0.023 x 10/sup -38/ cm/sup 2//GeV. These results are approx. 15% higher than previous measurements. Preliminary structure functions at low Q/sup 2/ are also presented.

Sigma

Charged current

Source

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Citations (1)

Spark-Gap-Trigger Amplifier

IEEE Transactions on Nuclear Science (1965)

Q. Kerns Harold W. Miller

Short over-all time delay, low time jitter, and excellent long-term reliability are among the desirable features designed into a pulse generator that produces a 2-MW output pulse 30 nsec after the application of a 1-V signal at its 50-ohm input connector. The 10-kV output pulse can be used to trigger simultaneously several spark gaps of the type used in spark-chamber pulse modulators. The 10 power gain of the spark-gaptrigger amplifier is achieved by four stages of amplification packaged in a 5-1/4 in. rack-mount chassis that operates directly from a 117-V line. The individual stages, each selected to give minimum time delay for a given power gain at their respective power levels are: avalanche transistors, planar triode, grounded-grid planar triode, and a triggered-spark gap. The techniques used for the last stage, a spark gap triggered by a corona light, are of particular interest since the same techniques are applicable to obtaining short time delays and long-term reliability from the larger spark gaps that the amplifier was designed to trigger. During 10 months of operation, there have been no failures and no adjustments necessary in any of the seven spark-gap trigger amplifiers used in various spark-chamber experiments at the Lawrence Radiation Laboratory of the University of California (UCLRL) in Berkeley.

Spark gap

Marx Generator

SPARK (programming language)

Triode

10.1109/tns.1965.4323541

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Citations (1)

The RF Control System of the NAL Accelerator

IEEE Transactions on Nuclear Science (1971)

M. Birk R. Ducar Q. Kerns G. Tool

The Booster and Main Accelerator RF Systems at NAL share many common devices and have nearly identical control requirements. The equipment for each cavity is controlled and monitored via a Module Interface Unit (MIU). The MIU's, connected to a MAC-16 computer via a 50 ohm parallel daisy chain cable system, serve the dual functions of interfacing the equipment to the computer and of providing facilities for manual control and monitoring of an accelerating module. The MIU is a general interface having the capacity to control 32 and monitor 128 binary lines, control 16 analog channels, and monitor 64 analog channels via an attached Multiplexed A/D Converter (MADC). The assignment of channels to equipment functions may be easily changed at each module. Each of three RF control centers contains a MAC-16 computer, an MIU and MADC for control of non-modular equipment, a timing controller to provide computer-controlled timing signals, and a computer-independent core memory curve generator providing repetitive driving waveforms. Each MAC-16 may be controlled locally using a portable I/O cart containing a teletype, paper tape reader, and control knobs, or from the main control room consoles via serial data links to a Sigma 2 computer.

Interfacing

Interface (matter)

10.1109/tns.1971.4326082

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Citations (1)

A Low Level RF System for the Fermilab Tevatron

K. Meisner H. Edwards James A. Fitzgerald Q. Kerns

by the 'bunch spreader' during acceleration to improve the smoothness of the spill. In the Tev I case, the 'bunch narrowing' procedure preceding {bar p} production and in bunch coalescing is facilitated by maintaining the smallest possible longitudinal emittance (i.e. the largest possible longitudinal phase space density). Also, during fixed target physics the Main Ring is essentially full (i.e. approx. 1090 of 1113 buckets occupied) so transient beam loading of the rf system is negligible except during injection, whereas for {bar p} production a single high intensity Booster batch (approx. 83 bunches) is to be accelerated causing substantial transient beam induced phase shift of the rf voltage during each passage. The low level phase and position error signals are normally derived from an essentially full ring during fixed target operation whereas in the Tev I program the systems must perform adequately with as few as ten adjacent buckets occupied. Because of the differences in emphasis between fixed target operation and Tevatron I operation is seems sensible to use separate low level rf systems for these two modes of operation. If a single low level system were to be used for both modes of operation some compromises may be necessary which might cause performance in either mode to be less than adequate. Because of the severe demands made on accelerator performance in the Tev I program it would seem reasonable to develop a unique system which can be optimized to the requirements.

Bunches

Fermilab

Booster (rocketry)

Transient (computer programming)

Beam emittance

Superconducting Super Collider

10.2172/1156257

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Citations (5)

Neutrino physics at the Tevatron

R. E. Blair F. S. Merritt Y. Fukushima R. Stefanski W. Marsh

Source

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Citations (0)

An R.f. Device for Precision Location of the Beam Position Detectors in the Energy Saver

IEEE Transactions on Nuclear Science (1983)

Q. Kerns G. Biallas F. Turkot R. Webber A. Wehmann

The task is to measure the center line of the beam detector with respect to the magnetic centerline with a precision of +-0.2 mm; the measurement must be made on 250 magnets (they come in 6 lengths, from 25'' to 99'') by a technician. Optical, mechanical, and electrical techniques for carrying out this procedure were considered. An RF device operating at 53 MHZ was adopted for the following reasons: (a) it provides complete electrical checkout of the hardware at operating frequency, including the bidirectional operation of the pickup, (b) no mechanical contact with the strip lines is required, and (c) the demands of production measurements and maintenance of calibration are better matched to the skills of an average technician. We describe the conceptual design, fabrication, and performance of this device.

Position (finance)

Beam energy

10.1109/tns.1983.4332778

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Citations (2)

Single bunch intensity monitoring system using an improved wall current monitor

C. D. Moore J. Crisp David M. Howard Q. Kerns Peter Martin

The length and intensity of individual beam bunches are important parameters in collider operations. A system for automatically measuring these parameters has been developed using a wall current monitor signal digitized by a 1 GHz sampling oscilloscope under microprocessor control. Bunch length and intensity are computed by the microprocessor and presented to the host computer. To verify the accuracy required, attention was given to the system's calibration and frequency response. The system has been successfully used to monitor colliding beam operations at Fermilab. The current 5% accuracy in measuring single-bunch intensity demonstrates the excellent fidelity and bandwidth of the system. The design of a resistive wall monitor with 3 kHz to 6 GHz bandwidth and less than 1 dB amplitude variation is presented. Using a microwave absorber inside the vacuum chamber to reduce noise is discussed.< >

Bunches

Microprocessor

Intensity

Resistive touchscreen

Photodiode

Fermilab

10.1109/pac.1989.73497

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Citations (17)