Tech Note Information

Name

Electron-Ion Collider (EC)

BNL Number

BNL-229872-2026-TECH

BNL Series Number

229872

Description/Abstract

Fast transverse beam instabilities represent one of the most challenging protection scenarios for the Electron-Ion Collider (EIC) electron storage ring (ESR). Coherent betatron oscillations driven by collective effects can grow rapidly and lead to substantial beam losses within only a few tens of turns, posing a threat to collimators, superconducting (SC) magnets, cryogenic systems, and detector components.\\\\\\\\\\\\\\\\r\\\\\\\\\\\\\\\\n\\\\\\\\\\\\\\\\r\\\\\\\\\\\\\\\\nA dedicated simulation framework based on distributed transverse excitations was developed to evaluate instability-driven beam losses in the ESR. A conservative instability rise time on the order of 10 turns was used to define a bounding protection scenario. Simulations show that the original two-collimator configuration is insufficient to localize losses under all operating conditions, whereas an optimized four-collimator configuration reduces loss leakage into protected regions by more than two orders of magnitude. Nevertheless, the most severe instability scenarios produce catastrophic beam impacts, with nearly half of the stored beam being intercepted by the collimators within a single turn, exceeding the preliminary estimated survivability limits of the baseline collimator design.\\\\\\\\\\\\\\\\r\\\\\\\\\\\\\\\\n\\\\\\\\\\\\\\\\r\\\\\\\\\\\\\\\\nThe results demonstrate that collimation alone is insufficient to guarantee safe ESR operation and must be complemented by a fast machine-protection system. Dedicated turn-by-turn beam-position monitors and fast beam-loss monitors provide sufficient advance warning to detect instability growth and initiate a beam abort before equipment-damaging loss levels are reached. These findings establish quantitative requirements for the ESR machine-protection architecture and support the implementation of a multilayer protection strategy for both accelerator and detector systems.\\\\\\\\\\\\\\\\r\\\\\\\\\\\\\\\\n

Publication Date

6/22/2026

Submittal Date

6/23/2026

Author Information

Primary Author

A. Natochii

DOE Subject Category

PARTICLE ACCELERATORS

Other Publication Number

EIC-ADD-TN-175