LANSCE QAC/DAQ Wire Scanner
Instrumentation Upgrade*L. Montoya†, S. Johnson, H.A. Watkins, D. Zimmermann - Los Alamos National Laboratory, Los Alamos, NM 87545, USAAbstract

High density instrumentation has been developed to upgrade wire scanner
beam diagnostic capability in all areas downstream of the Coupled Cavity
LINAC (CCL). Transverse beam profile measurements were originallyobtained using legacy electronics known as Computer AutomatedMeasurement and Control (CAMAC) crates. CAMAC has become obsolete,
and a new wire scanner diagnostic system was developed as a replacement.
With high wire scanner device density located in each area, instrumentation
was developed to meet that need along with the ability to interface with legacy
open-loop controlled actuators and be forward compatible with upgradedclosed-loop systems. A high-density system was developed using a Quad
Actuator Controller (QAC) and Data Acquisition (DAQ) chassis that pair
together using a sequencer when taking measurements. Software
improvements were also made, allowing for full waveform functionality thatwas previously unavailable. Deployment of 52 wire scanner locations in 2022
increased device availability and functionality across the facility. Hardware andsoftware design details along with results from accelerator beammeasurements are presented.

Controller Hardware

The electronic hardware consists primarily of two separate chassis, eachcontrolled using a National Instruments (NI) 9038 compact Reconfigurable
Input/Output (cRIO) packaged in 4U rack mountable enclosures configured
as input output controllers (IOC).
Quad Actuator Controller
The QAC chassis was designed to control up to four stepper motor
actuators, two actuators simultaneous. The chassis is compatible with both
open loop and closed loop motion control. Within the cRIO controller on theQAC is housed NI I/O modules, and serve as the interface between thewire scanner actuator and the cRIO and perform the functions as follows:• NI 9401 digital I/O for stepper
motor and brake control• NI 9421 sinking digital input
for limit switch indication• NI 9222 voltage input
potentiometer position
feed-back• RDK 9316 resolver todigital converter

Quad Actuator Controller

Data Acquisition
The DAQ chassis is capable of 32 channel, 100 kS/channel, simultaneouswaveform acquisition (10µs resolution) with a cPCI backplane with two highdensity 16 channel each, gain adjustable, 2 kΩ input impedence Analog
Front End (AFE) conditioning card capable of reading from 270 µA down to3 µA current levels.

Results

LANSCE User Facility

Vertical and Horizontal Axis Beam Profiles

Wire Scanner Hardware Diagram

System Overview

Wire scanners are electro-mechanical beam interceptive devices thatprovide cross-sectional beam profile measurements that describe beam
shape and position. A wire scanner system consists of an actuator to drive
the sense wires across the beam, and data acquisition to obtain the waveform data from the current induced by the secondary emitted electron yieldfrom the proton beam current im-pinging on the wire.
* This work was supported by the U.S. Department of Energy through the Los Alamos
National Laboratory. Los Alamos National Laboratory is operated by Triad National
Security, LLC, for the National Nuclear Security Administration of U.S. Department ofEnergy (Contract No. 89233218CNA000001). † lucasm@lanl.gov

Vertical and Horizontal Axis Waveform

Managed by Triad National Security, LLC, for the U.S. Department of Energy’s NNSA.

LA-UR-23-30152

Beamprofilemeasurements
weretaken using Long Bunch
Enable Gate beam, set to
4 Hz rep rate with 150 µs
beam length a Gaussian
profile was obtained.
The full waveform can beseen for the same scantaken with each trace awaveform
froma
separate beam pulse as
the wire scanned acrossthe beam.
All 52 wire scanner
locations
have
been
successfullyupgradedwith each device tested
and validated with beam,providing beam profile
measurements for eachlocation this past run
cycle.