Wire Position Monitoring with FPGA based Electronics

Eddy, N. ; Lysenko, O.

Fermi National Accelerator Laboratory

关键词: Modifications;    Simulation Instrumentation;    46 Instrumentation Related To Nuclear Science And Technology;    Digitizers;    Italy;   

DOI  :  10.2172/971001
RP-ID  :  FERMILAB-TM-2441-AD
RP-ID  :  AC02-07CH11359
RP-ID  :  971001

美国|英语

来源: UNT Digital Library

【 摘 要 】

This fall the first Tesla-style cryomodule cooldown test is being performed at Fermilab. Instrumentation department is preparing the electronics to handle the data from a set of wire position monitors (WPMs). For simulation purposes a prototype pipe with a WMP has been developed and built. The system is based on the measurement of signals induced in pickups by 320 MHz signal carried by a wire through the WPM. The wire is stretched along the pipe with a tensioning load of 9.07 kg. The WPM consists of four 50 {Omega} striplines spaced 90{sup o} apart. FPGA based digitizer scans the WPM and transmits the data to a PC via VME interface. The data acquisition is based on the PC running LabView. In order to increase the accuracy and convenience of the measurements some modifications were required. The first is implementation of an average and decimation filter algorithm in the integrator operation in the FPGA. The second is the development of alternative tool for WPM measurements in the PC. The paper describes how these modifications were performed and test results of a new design. The last cryomodule generation has a single chain of seven WPMs (placed in critical positions: at each end, at the three posts and between the posts) to monitor a cold mass displacement during cooldown. The system was developed in Italy in collaboration with DESY. Similar developments have taken place at Fermilab in the frame of cryomodules construction for SCRF research. This fall preliminary cryomodule cooldown test is being performed. In order to prepare an appropriate electronic system for the test a prototype pipe with a WMP has been developed and built, figure 1. The system is based on the measurement of signals induced in pickups by 320 MHz signal carried by a wire through the WPM. The 0.5 mm diameter Cu wire is stretched along the pipe with a tensioning load of 9.07 kg and has a length of 1.1 m. The WPM consists of four 50 {Omega} striplines spaced 90{sup o} apart. An FPGA based digitizer collects the WPM data and transmits it to the VME controller. The VME front-end processes the raw data to calculate positions and perform FFT. It is also provides the raw data to LabView running on a PC upon request. In order to increase the accuracy and convenience of the measurements some modifications were required. The first is connected with realization of average and decimation filter algorithm in the integrator operation in the FPGA. The second is connected with development of alternative tool for WPM measurements in the PC. We will discuss how these modifications were performed and test results of a new design.