ILC Upgrades to 3 TeV

TL;DR

This paper explores potential upgrade paths for the International Linear Collider (ILC) beyond 1 TeV, focusing on advanced superconducting structures and materials to achieve higher energies efficiently.

Contribution

It introduces novel superconducting structures and materials, such as travelling wave designs and Nb3Sn, for ILC energy upgrades beyond 1 TeV.

Findings

Traveling wave structures can achieve gradients of 70+ MV/m.

Nb3Sn cavities show potential for 80 MV/m at 4.2 K.

Significant improvements in R/Q impact power and heat load.

Abstract

We consider several ILC energy upgrade paths beyond 1 TeV depending on the needs of high energy physics. Parameters for four scenarios will be pre-sented and challenges discussed. 1. From 1 TeV to 2 TeV based on: A. Gradient advances of Nb cavities to 55 MV/m antici-pated from on-going SRF R&D on Nb structures. B. Radically new travelling wave (TW) superconducting structures optimized for effective gradients of 70+ MV/m, along with 100% increase in R/Q (discussed in more detail in paper WEOCAV04 at this confer-ence. The large gain in R/Q has a major beneficial impact on the refrigerator heat load, the RF power, and the AC operating power. OR 2. From 1 TeV to 3 TeV based on: A. Radically new travelling wave (TW) superconducting structures optimized for effective gradients of 70+ MV/m, along with 100% increase in R/Q. The large gain in R/Q has a major beneficial impact on heat load, RF power, and the AC operating power. B. 80 MV/m gradient potential for Nb3Sn with Q of 1x1010, based on extrapolations from high power pulsed measurements on single cell Nb3Sn cavities. Further, the operating temperature is 4.2 K instead of 2K due to the high Tc of Nb3Sn.