Abstract
Fission chambers are widely used in nuclear reactors, either occasionally to probe the neutron flux maps in nuclear power plants or as part of the nuclear instrumentation used in research reactors to characterize neutron flux levels in irradiation locations. Wide dynamic range acquisition systems are very limited in the nuclear instrumentation market. Thus, since 2012, CEA is developing the MONACO system, which allows measurement in pulse, fluctuation, and current mode running simultaneously on the same channel. The simultaneous use of three measurement modes places high requirements on the amplification stage. Indeed, the current mode exploits a bandwidth between 0 and a few kHz, while the fluctuation mode is based on the frequency range of 100 kHz 1MHz. Finally, for the pulse mode, it is necessary to identify current pulses of a few uA in amplitude and with a duration of about ten nanoseconds, which implies a bandwidth that extends up to 10 or 20 MHz. In the frame of the industrialization of the MONACO system, a new preamplifier was designed to meet those requirements. With a first prototype, LDCI and I-TECH performed very promising bench tests in October 2020. Tests with synthetic signals corresponding to pulse and fluctuation mode showed very good performance of the electronics. The positive and negative current pulses are correctly amplified and the measurement noise was estimated at 0.1 µApp thanks to proper electronic shielding. The DC measurement is also satisfactory in the tested range with an accuracy of less than nA and a bandwidth of 1kHz. Preamplifier qualifications are planned within realistic experiments using a fission chamber placed in a neutron field.
Highlights
THE MONACO system [1][2] (Multichannel Online Neutron Acquisition in Campbell mOde) was developed at CEA during the past 10 years until the TRL7 level and demonstrated its efficiency as a functional prototype for Fission Chamber (FC) signal acquisition
Within the commissioning of the new Jules Horowitz nuclear reactor, this system will be integrated into the experimental part of the data acquisition system
The industrialization of the MONACO system is a result of a mutual efforts between CEA who developed the prototype and Instrumentation Technologies
Summary
THE MONACO system [1][2] (Multichannel Online Neutron Acquisition in Campbell mOde) was developed at CEA during the past 10 years until the TRL7 level and demonstrated its efficiency as a functional prototype for Fission Chamber (FC) signal acquisition. This phase will consist of the redevelopment of the preamplifier frontend and of the modules that are critical for the MONACO system performance: the HV module, and the current measurement unit This phase was successfully concluded and will be described in the paragraphs of this paper. - Phase 2: Integration of a 4-channel system based on the hardware prototype developed in phase 1 This phase will expand the 1-channel integrated frontend to a fully functional 4-channel system with the integration of a digitizer unit aimed to collect and process the digitalized data. This paper will cover the first phase of the process where a functional pre-industrialization 1-channel version of the preamplifier was developed and tested
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
