Target development at HBS, Experimental Area Big Karl

Neutrons at a Compact accelerator-driven Neutron Source (CANS) are produced bynuclear reactions of light ions in the low MeV range impinging on a suitable targetmaterial. Within the HBS-project, we are developing a tantalum target whichmaximises the neutron yield for a 70 MeV proton beam able to withstand a heatdeposition of 100 kW. The produced neutrons with an average energy of around 1MeV need to be slowed down to thermal or cold energies depending on theinstrument requirements. The performance of this moderation process depends onthe materials and the geometry involved which requires the optimisation with MCNPand an experimental validation.For this we are planning to build a TMR prototype at the Big Karl experimental areaat the COSY facility which can be used to validate the MCNP simulations.Furthermore, it wil be used to deliver neutrons to basic neutron scatteringinstruments like e.g. a reflectometer.At the UNKEL workshop, I will present the current design of the target / moderator/ reflector assembly and the plans for the Big Karl experimental area where it will bebuild

HBS High Power Density Neutron Target - An approach to meet the special requirements of HiCANS

Within the framework of the Jülich High Brilliance Neutron Source (HBS) project, a high current accelerator based neutron source(HiCANS) is developed. The main power-limiting factor is the target that releases neutrons via nuclear reactions from theimpinging protons. The neutron yield of these nuclear reactions is quite small. This is compensated with a high proton currentwhich leads to a strong heat release inside the target. At the same time the target has to be very compact. Overall, this leads tounique requirements of the HBS target given by a 70 MeV pulsed proton beam on a surface area of 100 cm² with a peak current of100 mA and an average thermal power release of 100 kW inside the target. A solid tantalum target prototype with an innovativemicro channel water cooling structure was developed, manufactured, and tested at 1 kW/cm² with an electron beam to matchthese requirements. Known challenges from low energy targets like blistering, joining, lifetime, and heat dissipation, as well asparticular challenges of the HBS target design like coolant erosion, thermomechanical stresses, and critical heat flux have beenconsequently considered during the development. Here, we will present the HBS target design, explain various measures taken tosolve the challenges mentioned, and show the successful high heat flux tests in the electron beam facility JUDITH 2. This work ispart of the collaboration within ELENA and LENS on the development of HiCANS