Return-Path: Received: from [149.220.60.110] (account huebl@hzdr.de [149.220.60.110] verified) by hzdr.de (CommuniGate Pro SMTP 6.1.12) with ESMTPSA id 16408676 for picongpu-users@hzdr.de; Fri, 17 Feb 2017 15:34:43 +0100 To: picongpu-users@hzdr.de From: Axel Huebl Subject: [Bug in 0.2.3] Ionization: Fix Charge of Ionized Ions X-Enigmail-Draft-Status: N1110 Organization: HZDR Message-ID: Date: Fri, 17 Feb 2017 15:34:43 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Dear Users, The charge of all but hydrogen ion species, as seen by the PIC algorithm, was wrong *after ionizing an atom/ion*. Accidentally, the charge state inside our `GetCharge` trait was calculated as ``` proton number * ( proton number - bound electrons) ``` instead of ``` proton number - bound electrons ``` in case `chargeRatio` of the species in `speciesDefinition.param` was different from `1.0` (we usually set it to the fully ionized species' charge density). **Affected Setups** If *all of the following criteria* are true for at least one of your ion species, your simulation is affected: - your species in `speciesDefinition.param` used an `ionizer` - your species is not hydrogen - your species moves and/or creates currents (pusher, current solver) - you defined `chargeRatio` for that species different from `1.0` - you are using the latest stable release (0.2.3) or older Pre-ionized setups without ionization physics are unaffected. **Implications** The following quantities were falsely calculated: - plasma dynamics (pusher used wrong charge to mass ratio, current solver used wrong charge) - outputs to files (`fields/_chargeDensity`) Note that the wrong plasma dynamics resulting from that highly overcharged ion species is a severe bug and will likely render the complete simulation unphysical if the above mentioned criteria are met. **Kudos** Thanks to Thomas Kluge for reporting the issue. **Reference** https://github.com/ComputationalRadiationPhysics/picongpu/pull/1844 **Fixes** - the bug is fixed in `dev` since #1844 was merged yesterday - the bug will be fixed in a 0.2.4 release for "stable" Best regards, Axel Huebl -- Axel Huebl Phone +49 351 260 3582 https://www.hzdr.de/crp Computational Radiation Physics Laser Particle Acceleration Division Helmholtz-Zentrum Dresden - Rossendorf e.V. Bautzner Landstrasse 400, 01328 Dresden POB 510119, D-01314 Dresden Vorstand: Prof. Dr.Dr.h.c. R. Sauerbrey Prof. Dr.Dr.h.c. P. Joehnk VR 1693 beim Amtsgericht Dresden