Response of a tungsten powder target to an incident high energy proton beam

O Caretta,N Charitonidis,J O’Dell,C Densham,M Fitton,A Fabich,L Rivkin,T Davenne,P Loveridge,I Efthymiopoulos

doi:10.1103/physrevstab.17.101005

Abstract

The experiment described in this paper is the first study of the response of a static tungsten powder sample to an impinging high energy proton beam pulse. The experiment was carried out at the HiRadMat facility at CERN. Observations include high speed videos of a proton beam induced perturbation of the powder sample as well as data from a laser Doppler vibrometer measuring the oscillations of the powder container. A comparison with a previous analogous experiment which studied a proton beam interaction with mercury is made.

Highlights

A continuously flowing fluidized tungsten powder jet [1] has been proposed as a potential target technology for future high energy physics facilities
In-beam experiments demonstrated that a sample of tungsten powder immersed in a helium atmosphere is perturbed when impinged by a 440 GeV proton beam with a threshold intensity of around 4.6 × 1010 protons and a horizontal and vertical beam sigma of 0.45 mm and 1 mm respectively
This intensity threshold corresponds to a peak energy density of approximately 7.5 J=g in the tungsten grains

Summary

INTRODUCTION

A continuously flowing fluidized tungsten powder jet [1] has been proposed as a potential target technology for future high energy physics facilities (e.g., for a Neutrino Factory [2] or a compact neutron source). The fluidization of tungsten powder has been demonstrated off-line in a bespoke test facility [3], using both air and helium as the carrier gas Both open jets and contained flows of dense phase powder have been generated in a horizontal configuration suitable for a particle accelerator target system. The interest in measuring the perturbation velocity of the target material arises from the potential of high speed impacts being damaging to the surrounding containment This experiment is in many ways analogous to the stationary mercury thimble experiment. The powder experiment apparatus (Fig. 1) was designed to permit the observation of proton beam interactions with an open container of tungsten powder using high speed photography and laser-Doppler vibrometry (LDV). The LDV recorded for a total of 12 milliseconds, of which 1.2 ms were pretrigger

FLUKA SIMULATIONS

High speed camera

Findings

CONCLUSIONS