[Moller] Improved simulation of beam backgrounds and collimation at SuperKEKB

[James Fast]

Jay,
Thanks.  Interesting read.  It sounds like the primary issue with their simulations was really inaccurate models of the collimators (simulations killing particles outside an ellipse vs the actual rectangular jaws of the collimators) rather really bad simulations tools.  But indeed an interesting paper.  With JLab being essentially a single pass machine many of the complexities at SuperKEKB of multi-turn evolution of scattered beam are less severe.

James Fast
MOLLER Project Manager
Jefferson Lab
757-230-6833


From: Moller <moller-bounces at jlab.org> on behalf of Jay Benesch <benesch at jlab.org>
Date: Wednesday, April 7, 2021 at 8:43 AM
To: moller at jlab.org <moller at jlab.org>
Subject: [Moller] Improved simulation of beam backgrounds and collimation at SuperKEKB
This appears to be very relevant to MOLLER and the simulations now in progress.   (and if you're not on the Hall A collaboration mailing list and so didn't get the draft article on the MOLLER beam line changes, email me.)

https://arxiv.org/abs/2104.02645

Improved simulation of beam backgrounds and collimation at SuperKEKB
A. Natochii (1), S. E. Vahsen (1), H. Nakayama (2 and 3), T. Ishibashi (2), S. Terui (2) ((1) University of Hawaii, (2) High Energy Accelerator Research Organization, (3) The Graduate University for Advanced Studies)

    Mitigation of beam backgrounds via collimators is critical for the success of the Belle~II experiment at the SuperKEKB electron-positron collider. We report on an improved simulation methodology, which includes a refined physical description of the collimators and beam pipe, our first implementation of collimator tip scattering, and in which the existing beam particle tracking software has been embedded into a new sequential tracking framework. These improvements resolve longstanding discrepancies between measured and predicted Belle~II background levels, and significantly reduce the computing time required to optimize the collimation system in simulation. Finally, we report on collimator aperture scans, which confirm the accuracy of the simulation and suggest a new method for aligning the collimators.

Comments:        18 pages, 30 figures (including subfigures), 5 tables, to be submitted to PRAB
Subjects:        Accelerator Physics (physics.acc-ph); High Energy Physics - Experiment (hep-ex)
Cite as:         arXiv:2104.02645 [physics.acc-ph]
_______________________________________________
Moller mailing list
Moller at jlab.org
https://mailman.jlab.org/mailman/listinfo/moller
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/moller/attachments/20210407/b8b71ff8/attachment.html>