Presently, the Los Alamos National Laboratory is in the process of planning a refurbishment of various subsystems within its Los Alamos Neutron Science Center accelerator facility. A part of this LANSCE facility refurbishment will include some replacement of and improvement to existing older beam-diagnostics instrumentation. While plans are still being discussed, some instrumentation that is under improvement or replacement consideration are beam phase and position measurements within the 805-MHz side-coupled cavity linac, slow wire profile measurements, typically known as wire scanners, and possibly additional installation of fast ionization-chamber loss monitors. This paper will briefly describe the requirements for these beam measurements, what we have done thus far to answer these requirements, and some of the technical issues related to the implementation of the instrumentation.

There is presently an ongoing effort to develop beam position and phase measurements for the Los Alamos Neutron Science Center (LANSCE) linac associated with an improvement project known as the LANSCE Refurbishment. This non-interceptive measurement's purpose is to provide both measurements of beam phase for determining RF-cavity phase and amplitude set points, and position for determining the 805-MHz linac input beam transverse position and trajectories. The measurement components consist of a four-electrode beam-position and phase monitor (BPPM), a cable plant that transports the 201.25-MHz signals, electronics capable of detecting phase and amplitude signals, and associated software that communicates with a mature LANSCE control system. This paper describes measurement requirements, proposed beam line device, initial concepts for the associated electronics, and some of the issues developing beam measurements for an operational facility.

The recently completed 100-MeV H+ Isotope Production Facility (IPF) at the LANSCE will provide radioisotopes for medical research and diagnosis, for basic research and for commercial use. A change to the LANSCE accelerator facility allowed for the installation of the IPF. Three components make up the LANSCE accelerator: an injector that accelerates the H+ beam to 750-KeV, a drift-tube linac (DTL) that increases the beam energy to 100-MeV, and a side-coupled cavity linac (SCCL) that accelerates the beam to 800-MeV. The transition region, a space between the DTL and the SCCL, was modified to permit the insertion of a kicker magnet (23 o kick angle) for the purpose of extracting a portion of the 100-MeV H+ beam. A new beam line was installed to transport the extracted H+ beam to the radioisotope production target chamber. This paper will describe the commissioning and initial operating experiences of IPF.

The Spallation Neutron Source (SNS) linac accelerates 52-mA peak of pulsed H- particles to over 800 MeV. There are three types of accelerating structure in which the beam position must be measured: the drift-tube-linac (DTL); cavity-coupled-linac (CCL); and superconducting-linac (SCL)[1, 2]. Beam with a 402.5-MHz structure is injected into a 402.5 MHz DTL, followed by 805-MHz CCL and SCL structures. The position monitor pickups are all of the shorted-microstrip type with apertures of 2.5-cm, 3-cm and 7.3-cm-dia. In all cases, we down convert signals from the beam position pickups to a 50-MHz intermediate frequency (IF) for processing. We use the sampled in-phase and quadrature-phase (I&Q) processing technique to obtain the amplitude and phase information of the IF signals. All of the electronics are PCI-based hardware installed in PC computers employing standard technologies. LabVIEW/sup TM/ is used for all of the acquisition, processing, and serving of the data to ethernet, and hence, the control system. The design of this beam position system hardware is described herein.