Engineering topics

Gruchalla, Michael E

Publications and source records attributed to Gruchalla, Michael E.

7 records

DOE OSTI2012

Wide-Bandwidth Capture of Wire-Scanner Signals

Integrated charge collected on the sense wires of wire-scanner systems utilized to determine beam profile is generally the parameter of interest. The LANSCE application requires capturing the charge information macropulse-by-macropulse with macropulse lengths as long as 700 {micro}s at a maximum macropulse rate of 120 Hz. Also, for the LANSCE application, it is required that the integration be performed in a manner that does not require integrator reset between macropulses. Due to the long macropulse which must be accommodated and the 8.33 ms minimum pulse period, a simple R-C integrator cannot be utilized since there is insufficient time between macropulses to allow the integrator to adequately recover. The application of wide analog bandwidth to provide accurate pulse-by-pulse capture of the wire signals with digital integration of the wire signals to determine captured charge at each macropulse in applications with comparatively long macropulses and high pulse repetition rates is presented.

43 PARTICLE ACCELERATORS↗

DOE OSTI2012

Mechanical Design and Evaluation of the MP-11-Like Wire Scanner Prototype

A wire scanner (WS) is a linearly actuated diagnostic device that uses fiber wires (such as Tungsten or Silicon Carbide) to obtain the position and intensity profile of the proton beam at the Los Alamos Neutron Science Center (LANSCE) particle accelerator. LANSCE will be installing approximately 86 new WS in the near future as part of the LANSCE Risk Mitigation project. These 86 new WS include the replacement of many current WS and some newly added to the current linear accelerator and other beam lines. The reason for the replacement and addition of WS is that many of the existing actuators have parts that are no longer readily available and are difficult to find, thus making maintenance very difficult. One of the main goals is to construct the new WS with as many commercially-available-off-the-shelf components as possible. In addition, faster beam scans (both mechanically and in term of data acquisition) are desired for better operation of the accelerator. This document outlines the mechanical design of the new MP-11-like WS prototype and compares it to a previously built and tested SNS-like WS prototype.

42 ENGINEERING↗

DOE OSTI2012

Wire Scanner Beam Profile Measurements for the LANSCE Facility

The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected transverse-beam distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new WS beam profile measurement is being designed, fabricated, and tested. The goals for these new WS's include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based client software). This WS measurement system will measure Hand H{sup +} LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

43 PARTICLE ACCELERATORS↗

DOE OSTI2012

Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development

The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H{sup -} beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

43 PARTICLE ACCELERATORS↗

DOE OSTI2011

LANSCE-R WIRE-SCANNER SYSTEM

The National Instruments cRIO platform is used for the new LANSCE-R wire-scanner systems. All wire-scanner electronics are integrated into a single BiRa BiRIO 4U cRIO chassis specifically designed for the cRIO crate and all interface electronics. The BiRIO chassis, actuator and LabVIEW VIs provide a complete wire-scanner system integrated with EPICS. The new wire-scanner chassis includes an 8-slot cRIO crate with Virtex-5 LX 110 FPGA and Power-PC real-time controller, the LANL-developed cRIO 2-axis wire-sensor analog interface module (AFE), NI9222 cRIO 4-channel 16-bit digitizer, cRIO resolver demodulator, cRIO event receiver, front-panel touch panel display, motor driver, and all necessary software, interface wiring, connectors and ancillary components. This wirescanner system provides a complete, turn-key, 2-axis wire-scanner system including 2-channel low-noise sensewire interface with variable DC wire bias and wireintegrity monitor, 16-bit signal digitizers, actuator motor drive and control, actuator position sensing, limit-switch interfaces, event receiver, LabVIEW and EPICS interface, and both remote operation and full stand-alone operation using the touch panel.

Accelerator Design, Technology, and Operations↗

DOE OSTI2011

LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS

A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments Compact RIO (cRIO) module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal dataacquisition system, and wire bias of 0V to +/-50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.

Accelerator Design, Technology, and Operations↗

DOE OSTI2011

Lansce Wire Scanning Diagnostics Device Mechanical Design

The Accelerator Operations & Technology Division at Los Alamos National Laboratory operates a linear particle accelerator which utilizes 110 wire scanning diagnostics devices to gain position and intensity information of the proton beam. In the upcoming LANSCE improvements, 51 of these wire scanners are to be replaced with a new design, up-to-date technology and off-the-shelf components. This document outlines the requirements for the mechanical design of the LANSCE wire scanner and presents the recently developed linac wire scanner prototype. Additionally, this document presents the design modifications that have been implemented into the fabrication and assembly of this first linac wire scanner prototype. Also, this document will present the design for the second, third, and fourth wire scanner prototypes being developed. Prototypes 2 and 3 belong to a different section of the particle accelerator and therefore have slightly different design specifications. Prototype 4 is a modification of a previously used wire scanner in our facility. Lastly, the paper concludes with a plan for future work on the wire scanner development.

Accelerator Design, Technology, and Operations↗