Tertiary particle production and target optimization of the H2 beam line in the SPS North Area

TL;DR

This study evaluates tertiary particle yields from various targets in the SPS North Area's H2 beam line across multiple energies, aiming to optimize target design, understand proton production, and compare simulation models for future experiments.

Contribution

It provides a comprehensive analysis of target materials and geometries for particle production, including a benchmark of GEANT-4 physics lists in the 50-250 GeV/c range.

Findings

Optimal target configurations identified for maximum particle yield.

Proton to pion production ratios analyzed for different targets.

Differences between physics lists QGSP_BIC and FTFP_BERT demonstrated.

Abstract

In this note, the tertiary particle yield from secondary targets of different materials placed at the 'filter' position of the H2 beam line of SPS North Area are presented. The production is studied for secondary beams of different momenta in the range of 50-250 GeV/c. More specifically, we studied six different targets: two copper cylinders with a radius of 40 mm and lengths of 100 and 300 mm, one solid tungsten cylinder with a radius of 40 mm and a length of 150 mm and three polyethylene cylinders with radius of 40 mm and lengths of 550, 700 and 1000 mm. Eight different momenta of the secondary beam (50, 60, 70, 100, 120, 150, 200 and 250 GeV/c) as well as two different physics lists (QGSP_BIC and FTFP_BERT) have been extensively studied. The purpose of this study is (a) to optimize (using the appropriate filter target) the particle production from the secondary targets as demanded by the experiments (b) investigate the proton production (with respect to the pion production) in the produced tertiary beams, a fact interesting for cross-section measuring experiments (e.g. NA61), (c) provide an expected beam-composition database for each target and energy that will act as a reference for the test-beam users of the North Area and (d) demonstrate the differences between the different GEANT-4 physics lists. Moreover this work constitutes a starting point for a more detailed benchmark of the different available Monte-Carlo models and codes in this momentum range.