Proton Improvement Plan II Cryogenic Distribution System thermodynamic design

TL;DR

This paper presents the thermodynamic design of the cryogenic helium distribution system for Fermilab's PIPII superconducting linear accelerator, focusing on heat load management, pressure control, and operational modes.

Contribution

It introduces a preliminary thermodynamic design tailored to PIPII's cryogenic requirements, including sizing, operating modes, and special cooling considerations.

Findings

Design accommodates multiple temperature levels (80 K, 5 K, 2 K).

System ensures controlled cooldown and pressure management.

Calculated mass flow capacities meet operational demands.

Abstract

The Proton Improvement Plan II (PIPII) is a superconducting linear accelerator being built at Fermilab that will provide 800 MeV proton beams for neutrino production. The Linac requires cooling at 80 K, 5 K, and 2 K temperatures, which will be provided by cryogenic helium produced by a Helium Cryoplant and distributed by a Cryogenic Distribution System (CDS). Based primarily on the Linac heat load requirements at each temperature and the allowable pressure drop, we have made a preliminary thermodynamic design of the CDS. The design also incorporates special requirements such as controlled and or fast cooldown of the superconducting RF cavities and their dual maximum allowable working pressure. This paper presents the overall features of the PIPII CDS, sizing of helium process circuits, different operating modes, and calculated mass flow capacities that cater to these operating modes.