Speaker
Description
The construction of an electron–positron collider 'Higgs factory' has been stalled for a decade, not because of feasibility but because of the cost of radio-frequency (RF) acceleration. Plasma-wakefield acceleration promises to alleviate this problem due to its orders-of-magnitude higher accelerating gradients, which result in a significant cost reduction based on a sizeable reduction in footprint. However, plasma-based acceleration of positrons is much more difficult than for electrons. We propose a collider scheme that avoids positron acceleration in plasma, using a mixture of beam-driven plasma-wakefield acceleration to high energy for the electrons and conventional RF acceleration to low energy for the positrons. Here we emphasise the benefits of HALHF with regards to sustainability via a sizeable reduction in carbon emissions during construction - due to the reduced footprint - and possibly also during operation - due to the in-principle higher energy-transfer efficiencies compared to RF.
