P. Nieminen & M.G. Pia Achievements of the LowE e.m. WG Petteri Nieminen & Maria Grazia Pia Geant4 Workshop Paris, 16-20 October 2000

P. Nieminen & M.G. Pia

Achievements of the LowE e.m. WG

Petteri Nieminen & Maria Grazia Pia

Geant4 Workshop

Paris, 16-20 October 2000

http://www.ge.infn.it/lowE/


Birth and growthof the Low Energy e.m. Physics WG

We applied for the creation of a new LowE e.m. WG in March 2000

WG created by the CB in April 2000 9 members at the time of the creation

3 of the initial members lost including holder of full time contract

33 members now 3 new applications to be examined

this week by CB/TSB 3 new affiliations of existing

collaborators Contacts in progress with 3 new

groups interested to join


How we work

Promotion of cross-WG activities Close relationship with user communities

Regular Working Group meetings Emphasis on training of all group members

Active strategy of talks and publications for promotion of Geant4 and our own products as an incentive and reward for the group members

Goal-directed project management

Spiral cyclic software processCharacterized by

Wide spectrum of development:Physics

Applications


Milestones

LowE e.m. Milestone Document, TSB April 2000

Assessment of the physics implementation

Physics updates and extensions

Software quality and software process improvement

Testing

Design improvement

Documentation and promotion


Assessment

Thorough assessment of the existing software

design implementations physics performance testing tools

Comparisons with experimental data Comparisons with Standard e.m.

processes in common validity range for debugging purpose

bugs and problems found and corrected

both in LowE and Standard...

Close collaboration with user groups in the assessment

Application to microdosimetry and nanodosimetry


New physics

New model for positive charged hadrons (Ziegler 1985) Improvements on straggling (hadrons and ions) Introduction of a dynamic dependence on effective charge

into the range calculation Improvements in the validity range of ray production New models for ion energy loss fluctuations New model for negative charged hadrons

first model was limited to a set of materials then extended to all elements, based on theoretical calculations

OO Analysis started for positrons


0.01 0.1 1 100.01

0.1

1

10

100

1000

Geant4 LowEn NIST

/ (

cm 2

/g)

in ir

on

Photon Energy (MeV)

0.01 0.1 1 10

0.1

1

10

Geant4 LowEn NIST

/

(cm

2 /g

) in

wat

er

Photon Energy (MeV)

0.01 0.1 1 10-16

-14

-12

-10

-8

-6

-4

-2

0

2

4

6

8

10

12

14

16

Delta = (NIST-G4EMStand) / NIST Delta = (NIST-G4LowEn) / NIST

Del

ta (

%)

Photon Energy (MeV)

0.01 0.1 1

0.01

0.1

1

10

100

Geant4 LowEn NIST

/ (

cm 2

/ g

in le

ad

Photon energy (MeV)

0.01 0.1 1-10

-8

-6

-4

-2

0

2

4

6

8

10 E = (NIST - G4EM Standard)/NIST E = (NIST- G4LowEn)/NIST

E (

%)

Photon Energy (MeV)

Results, photons

water Fe Pb

0.01 0.1 1 10-18-16-14-12-10-8-6-4-202468

1012141618

E = (NIST-G4EMStandard)/NIST E = (NIST-G4LowEn)/NIST

E (

%)

Photon Energy (MeV)


Results, protons and ions


Plans for extensions

Foreseen extensions include:

polarisation in conversion

polarisation in Compton effect

Doppler broadening

Auger electrons

models to handle material dependent effects at very low energies

reengineering of Penelope models into Geant4

components of interest for space/astrophysics applications

components of interest for medical applications


Software Process Improvement

Huge effort invested into SPI started from level 0 chaotic, left to heroic improvisation

On-going process the results of the assessment are

probably already quite obsolete for the LowE e.m. WG...

A sample of the improvements: establishment and management

of User Requirements Document

establishment and documentation of procedures

design before coding designs and testing under

configuration management identification of tasks and

responsibilities tracking

...too long to list all the improvements


Internal training

Substantial investment in the internal training in the WG guided readings code reviews mentoring introduction to basic concepts in software process and OO methodologies

Visible effects on the quality of the software and of the process

Great interest among the developers who demand more of it

Perhaps a suggestion for a collaboration-wide programme?


Testing

Two system tests

No unit tests

No testing procedures

Physics tests in personal accounts only

No distinction between tests and examples

Suite of unit tests

Suite of physics tests

Two system tests

Tests and examples are separated

Testing procedures

Testing integrated with development

from... to...


Design

Initial situation: no architectural nor detailed design no design process

Massive improvement of the design and design process needed spiral cyclic process design iteration in the hadron/ion domain design documentation

Reverse engineering of existing classes

Further design iterations already planned

Education to design and design process in the WG


from...

Top level class diagramRD44 Geant4alpha


Top level class diagram

obtained from reverse engineering...

to...


Design: electrons

from...


Design: electronsto...


Design: photons

from...


Design: photonsto...


Design:hadrons, ions

from...

(reverse engineering...)


to...


Documentation

User Documentation Included LowE documentation in Application Developer Guide Expanded LowE documentation in Physics Reference Manual Identified wrong documentation in Toolkit Developer Guide

Internal documentation• procedures design tests

Web page

http://www.ge.infn.it/lowE/


Conferences 2000-2001

CHEP 2000 (2) Padova, February ESA-CERN workshop CERN, April PTCOG Uppsala, April ICCR Heidelberg, May Workshop on Space Radiation Research Arona, May ESTRO Istanbul, September Calor 2000 Annecy, October MC 2000 (3) 3 INFN preprints Lisbon, October AIRO Pisa, October ESTEC TOS-EMA Final Presentation Days ESTEC, December

Seminars (DESY, Frascati, Genova, Rome, Stockholm, Udine)


Publications

General LowE paper

Electrons and photons

Positive hadrons

Ions

Antiprotons

Microdosimetry

Space telescope general facility

Brachytherapy general facility

Brachytherapy comparison project

Design of the LowE package

The following publications on refereed journals are planned in the short term:

Drafts already available for some of them


Other activities

Three advanced examples developed by the LowE WG X-ray telescope -ray telescope brachytherapy

to be released in December

Collaboration with AIDA analysis tools group Collaboration with other WGs: UI/GUI, Visualisation

The examples/advanced directory has been empty since the time of the Niigata Workshop (July 1998)...


The user community The WG promotes close contacts with its users Large user community, in expansion

excellent relationships with our users users often contact us directly the promotion through conferences, seminars, and web pages plays a

fundamental role in the contacts with user communities URD created, maintained and regularly updated Fruitful collaboration with users on testing

“I really appreciate your support and I know you are doing your best. If youneed any additional information, do not hesitate to contact me.”

“Thank you very much for pointing out the pertinent parameters.I truly appreciate the time and effort you put into answering my questions.”

Excerpts of communications with users on Problem Reports:


Conclusions

We fulfilled all our milestones.

On time.

We hope to have demonstrated to the Collaboration that the creation of the LowE e.m. WG has been fruitful to Geant4

Documents

P. Nieminen & M.G. Pia Achievements of the LowE e.m. WG Petteri Nieminen & Maria Grazia Pia Geant4 Workshop Paris, 16-20 October 2000