10th Geant4 Space Users Workshop

27 May 2014, 08:00 → 29 May 2014, 18:00 US/Central

Jackson Center, Huntsville, Alabama, USA

The main workshop web page is here.
http://www-public.slac.stanford.edu/geant4/G4SUW2014/

Tuesday, 27 May

Registration

Session 1 - Welcome and general status reports

Convener: Dr Robert Weller (Vanderbilt ISDE)

1 Welcome

Speaker: Dr Dale Thomas (NASA/MSFC Associate Director Technical)

2 Status report from NASA/MSFC

Speaker: Dr Abdulnasser F. Barghouty (NASA/MFSC)

Slides 10thGSUW_SpaceRadiation.pptx

3 Status report from NASA/JPL

4 Status report from JAXA

JAXA and other Japanese space activity around Geant4 will be reported.

Speaker: Dr Masanobu Ozaki (JAXA)

Slides StatusReportFromJAXA_ozaki.pdf

10:30 break

Session 2 - General status reports

Convener: Dr Abdulnasser F. Barghouty (NASA/MSFC)

5 Invited talk - Space Launch Systems update

Speaker: Dr Keith Hefner (NASA Space Launch System Program Office - Associate Program Manager)

6 Status report from ESA

Speaker: Mr Petteri Nieminen (ESA)

Slides ESA_Geant4_RD_activities_2014.pptm

7 Report from the 2014 International Space Development Conference

The International Space Development Conference is presented annually by the National Space Society and is attended by scientists, engineers, entrepreneurs and students interested in space exploration and exploitation. Topics range from space science to space settlement and include engagement and outreach programs. This talk will present a summary of interesting topics and impressions from the conference as well as excerpts from the Geant4 radiation protection talk presented there.

Speaker: Dr Dennis Wright (SLAC)

Slides SUWISDC.pdf

8 Discussion

12:30 Lunch break

Session 3 - Space missions : instruments and detectors

Convener: Dr Scott Miller (NASA/MSFC)

9 Advanced Neutron Spectrometer Simulation

A Geant4 simulation of the Advanced Neutron Spectrometer (ANS) will be described. ANS uses a volume of vinyltoluene scintillator with embedded scintillating glass fibers composed of 20% Li2O-15% MgO-64.4%SiO2-0.6%Ce2O3 with the lithium being 95% Li-6. Neutrons would be captured in the glass which has different scintillation characteristics in terms of spectral output and timing from vinyltoluene scintillator. The capture interaction here is n+Li-6->alpha+triton where the triton energy is 2.734 MeV and the alpha energy is 2.105 MeV. To reach energies where this interaction is probable the neutron must be at near thermal energies having lost energy through elastic scattering in the vinyltoluene scintillator. The approach in ANS is to identify the unique light pulse associated with a neutron capture event in the glass fiber and use the total light produced earlier in the vinyltoluene scintillator as a measure of primary neutron energy deposited in the detector volume. A GDML description of the ANS geometry and the appropriate materials was constructed for input into a Geant4 simulation tailor to transport neutron and describe the response of the various parts of the detector in detail. A key part of the simulation is the description of the optical characteristics of the scintillator material, the scintillator volume surface characteristics, and the optical coupling between the scintillator and the photomultiplier tube.

Speaker: Mr John Watts (physicist)

Slides Advanced_Neutron_Spectrometer_Geant4_Simulations.pptx

10 Geant4 simulation of extensive air showers

The Extreme Universe Space Observatory (EUSO) is a new type of observatory that uses Earth’s atmosphere to detect the Extreme Energy Cosmic Rays (EECRs), those with energies in excess of 1018 eV. Studies of the nature of EECRs provide us with some information about the origin, acceleration and propagation of the primary cosmic rays. Such studies are based on the interpretation of the extensive air showers (EASs) measurements, which are cascade of particles generated in the atmosphere. A Geant4 application is under development to simulate EASs induced by primary cosmic ray particles. Calculations of EASs induced by protons and Iron beams above TeV will be presented and discussed.

Speaker: Dr Mohammad Sabra (NASA/MSFC)

Slides G4SUWTalk_MSabra.pdf

11 Geant4 in ASTRO-H observatory development

ASTRO-H is an international X-ray observatory scheduled to be launched in 2015. To design a low particle and X-ray background structure and estimate the in-orbit background for observations planning, Geant4 acts as the central engine of the Monte Carlo simulation. Here we will present about the cosmic X-ray background shield study and the comparison between Geant4 ver.10 activation and a beam experiment data in short (1-20 min) time scale.

Speaker: Dr Masanobu Ozaki (JAXA)

Slides Geant4inASTRO-HObservatoryDevelopment_ozaki.pdf

15:30 break

Session 4 - Single event effects

Convener: Dr Masanobu Ozaki (JAXA)

12 3D TCAD and Mixed-Mode Simulation of Devices and ICs with Complex Nuclear Events from MRED/Geant4

Resolution of fine features is paramount for correctly describing the physics of device response to nuclear event. TCAD and circuit-device (mixed-mode) tools coupled with MRED/Geant4 for automated simulations of nanoscale complex nuclear event effects from ion tracks in integrated circuits devices are presented. 3D CFDRC NanoTCAD simulator includes automatic building of 3D models from integrated circuit layouts (GDSII), and generating and adaptation of computational mesh to fine nanoscale features of multi-branched high energy ion tracks produced by Vanderbilt University MRED/Geant4 package. Generation and parallel simulation of hundreds (or thousands) of events is automated with minimal user intervention. This approach allows significant increase in computation efficiency.

Speaker: Dr Alex Fedoseyev (CFDRC)

13 Geant4 and Microelectronics - Recent Successes, Looming Concerns

Speakers: Dr Robert Reed (Vanderbilt ISDE), Prof. Robert Weller (Vanderbilt ISDE)

Slides Weller_Reed_for_upload.pptx

Wednesday, 28 May

Session 5 - Status reports from Geant4 developers

Convener: Andrea Dotti (SLAC National Accelerator Laboratory)

14 General status updates and perspectives

Speaker: Dr Makoto ASAI (SLAC)

Slides Geant4GeneralStatus.pdf

15 Highlights in EM physics in v10.0

Speaker: Dr Tatsumi Koi (SLAC)

Slides 1405G4SW_EMPhysics.pdf

16 Highlights in hadronic physics in v10.0

Speaker: Dr Dennis Wright (SLAC)

Slides SUWDHW.pdf

10:15 break

Session 6 - Status reports from Geant4 developers / Geant4 Technical Forum

Convener: Dr Dennis Wright (SLAC)

17 Highlights in condensed matter (and other) physics

Speaker: Andrea Dotti (SLAC National Accelerator Laboratory)

Slides G4CMP-SUW.pdf

18 Isomer production in v10.0

Speaker: Dr Tatsumi Koi (SLAC)

Slides 1405G4SUWS_Isomer.pdf

12:00 Lunch break

Social event - Tour and Banquet

Thursday, 29 May

Session 7 - Radiation effects

Convener: Mr Ashok Raman (CFDRC)

19 Application of a Systems Biology-based Approach to Infer Damage Mechanisms and Health Effects of Space Radiation

Exposure to space radiation and the associated health risks pose a major challenge to the growth of deep space exploration. The effects of such radiation on electronics and shielding have been studied in considerable detail and have led to novel methods and design strategies for minimizing equipment failure and developing hardening strategies. Similar efforts to better understand the effects of space radiation on human health utilize techniques such as DNA strand breaks, cytogenic analysis and molecular markers, and are often used to measure the late-effects of exposure to radiation. However, these approaches require sophisticated equipment, are typically based on destructive analysis of cells and are time consuming. There is a clear need for the development and validation of the early stage biomarkers of radiation exposure, which could lead to the development of improved therapeutic protectants, targeted drug delivery or other countermeasure or can be used to mitigate the severity of radiation exposure. In this context, we have developed and validated a systems biology based approach for identifying biomarkers from genomic samples. Our approach integrates features of the detected signaling pathways to construct a comprehensive network model. Cells exposed to different doses of radiation are analyzed for changes in gene expression. The upregulated or downregulated genes are used to automatically build a pathway model integrating diverse mechanism of action. A Boolean logic-based simulation of these complex pathways is used to determine an Active Core Pathway that captures the principal responses of the radiation exposure. Network modeling and analysis is subsequently applied to the cellular pathways to discover and rank biomarkers of radiation exposure. Model predictions are validated is performed by comparing with experimental studies. This approach can be integrated downstream of currently used software tools that compute dosages and energy-deposition in biological tissue (e.g., Geant4 DNA module) when an astronaut is exposed to radiation. Detection of one or more of the predicted radiation biomarkers of early-exposure can serve as a starting point for application of relevant therapeutics or countermeasures.

Speaker: Dr Ravishankar R. Vallabhajosyula (CFD Research Corporation (CFDRC))

20 Using SPENVIS fo SUDA radiation modeling

We will present our first simulation results for TIDs for the SUDA instrument (SUrface Dust Analyzer) considered by ICEE for the Clipper mission. We will describe our workflow, experience with SPENVIS and share our recommendations for the shield design.

Speaker: Svetlana Shasharina (Tech-X Corporation)

Slides SUDAG4SU2014.pdf

21 A CUDA-based Monte Carlo Simulation for Radiation

In this talk we will describe a joint project between Stanford University, SLAC, KEK and NVIDIA for the development of a radiation therapy simulation system based on Geant4 physics that runs on GPUs. The system is capable of performing radiation simulation with electron and gamma primaries on voxelised geometries for the calculation of deposited dose in the voxels. The methodology implemented will be presented together with preliminary validation results and the speed-up gain obtained with respect to an equivalent CPU code based on full Geant4 simulation.

Speaker: Andrea Dotti (SLAC National Accelerator Laboratory)

Slides G4CUDA.pdf

10:30 break

Session 8 - Software tools

Convener: Dr Tatsumi Koi (SLAC)

22 A multi-format multi-geometry interface for Geant4/GRAS

The use of Geant4 to perform advanced space radiation analyses, over realistic S/C or P/L geometries, usually requires the radiation engineers to model the mass world combining a CAD/CAE design describing the mechanical structure, in turn an assembly of parts developed in parallel by collaborating teams, with specific Geant4 geometries natively built in GDML or with alternative descriptions coming from other physics simulation codes, such as TCAD tools for device simulation or the SPIS toolkit for plasma interaction. Although there already exists solutions to import CAD/CAE designs, via STEP-GDML converters, or translate SPIS mesh geometries into Geant4, via specific Gmsh developments during the ELSHIELD project, however there is no common interface to load and combine multiple geometrical descriptions into a single simulation world. A new set of new Geant4/GRAS geometrical classes will be presented, showing how users can easily load several geometrical designs, defined in the same or different format, and assemble them arbitrarily. Current implementation provides interfaces to combine files in GDML, Gmsh and STEP (via Gmsh) format. In addition, a preliminary geometry parser for TCAD layouts, based on CIF format, will be also presented.

Speaker: Mr Sergio Ibarmia (INTA)

Slides ibarmia_MultiGeometry_G4SUWS_2014.pdf

23 Towards CAD, GUI, and materials combining with Geant4

This discusses and effort to develop a GUI to allow efficient use of CAD within Geant4, including the ability to import, combine materials, and do fast modeling based on DAGMC. A demo will be shown.

Speaker: Dr John Cary (Tech-X Corporation)

Slides 20140528Cadg4SpaceApp.pdf

24 Geant4 Simulations Activities at JPL

My presentation will show several Geant4 applications developed past few months for Europa mission and others at JPL. The focus will be on adaptation of GDML to create a few complicated models via FASTRAD. I will show some Geant4 models and report preliminary test results.

Social event - luncheon seminar

Luncheon seminar sponsored by CFDRC is held on May 29th (Thursday). The guest speaker is a retired NASA astronaut Dr. Jan Davis, who is currently Vice President and Deputy General Manager at Jacobs. All workshop participants are invited.

Session 9 - Radiation environments and shielding

Convener: Dr Robert Reed (ISDE/Vanderbilt University)

25 Geant4 Simulations of Space Radiation Sensors at The Aerospace Corporation

Geant4 is a vital tool for understanding and calibrating the response of space-borne radiation sensors at The Aerospace Corporation. In the year since the last Geant4 Space Users' Workshop, we have taken advantage of new physics lists that include nuclear interactions of heavy ion projectiles on heavy ion targets to improve our understanding of the response of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) aboard the Lunar Reconnaissance Orbiter as it measures the galactic cosmic ray (GCR) environment. We have also used these improvements in Geant4 physics to model the production of secondary particles under GCR bombardment of the lunar surface, which are also measured by CRaTER, and we plan to perform a similar calculation for GCR secondaries produced by Earth's atmosphere, the neutrons among which create the protons trapped in the Inner Van Allen Belt as they decay in flight. Aboard the Van Allen Probes, we are in the process of modeling the detailed response of the Magnetic Electron/Ion Spectrometer (MagEIS) sensor heads, starting with the high-energy electron head that nominally responds to electrons of a few MeV but that also has background from higher-energy electrons and penetrating protons. We are also continuing to refine our understanding of the Relativistic Proton Spectrometer to the highest-energy protons in the magnetosphere and to GCRs, modifying our simulations to better reproduce the observations.

Speaker: Dr Mark Looper (The Aerospace Corporation)

Slides looper_trim.pdf

26 Simulating the detector response of MAVEN's Solar Energetic Particle (SEP) instrument with Geant4

The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission will orbit Mars to improve our understanding of how Mars lost most of its atmosphere. Launched in November 2013, MAVEN will go into orbit around Mars in September 2014. Its payload consists of several complementary instruments (in situ and remote sensing), including the two Solar Energetic Particle (SEP) detectors. Simulations in Geant4 have been used to determine the thickness of the "dead" layer of the detectors, as well as the low-energy geometric factor. More importantly, simulations are currently in progress to observe the instrument's response to several particle types with a large range of initial energies. The results of these simulations will be used (via convolution) to improve the interpretation of actual energy deposits recorded by SEP.

Speaker: Mr Patrick Dunn (University of California, Berkeley)

Slides Geant4_10th_Workshop_Huntsville.pdf

27 Multithreading capabilities in v10.0

Speaker: Andrea Dotti (SLAC National Accelerator Laboratory)

Slides MT_Status_in_V10_for_Space_User_Workshop.pdf

15:30 break

Session 10 - Open discussion and workshop closing

Convener: Dr Makoto ASAI (SLAC)

28 How to migrate to multithreading

Speaker: Dr Makoto ASAI (SLAC)

Slides HowToMigrateToMultiThread.pdf

29 Open discussion and workshop closing