SPIDER neutron diagnostic: Overall System Description

This document presents advances in the design of th e CNESM neutron diagnostic for SPIDER. It is submitted as Progress Report P1.1 of subtask T3.5 o f the F4E contract F4E-RFX-PMS_A-WP-2015. This is an update of the previous version, RFX_SPID ER_TN_169_r3, submitted as deliverable of the F4E contract F4E-RFX-PMS_A-WP-2014. This report describes the design of the CNESM diagn ostic for SPIDER. The active part of the diagnostic is constituted by the nGEM detector whose design is fully described here together with all the services that are needed for its operation (gas system, HV system and DAQ system ). The test of nGEM detector prototypes are described in report RFX_SPIDER_TN_170_r4. The report comprises the design of the detector box together with its integration with the beam dump a nd acceptance criteria (mainly concerning vacuum seali ng), its installation/removal procedures and all th e related services. The system design has progressed in 2015 in the fol lowing areas: - Completion of the CNESM engineering design relate d to: - definition of the final detector position inside the SPIDER beam dump, - estabilishment of the final path of all the cable s and pipes serving the diagnostic and choice of th e tombak (after interaction with company) - Definition of the electrical scheme of the diagno stic - Study of the temperature variation of the detecto r box following heat exchange with the beam dump du ring SPIDER pulses Risk management was also addressed. No major cause of concern could be foreseen.