1. JUNO Offline Geometry Management
Kaijie Li, Zhengyun You
Sun Yat-sen University 威海

2. Outline JUNO Experiment Overview Identifier Geometry Service
CentralDetector
WaterPool
TopTracker
Parameter Management
Summary

3. JUNO Experiment Jiangmen Underground Neutrino Observatory (JUNO)
Reactor Neutrino Experiment (baseline 53km)
Inverse beta decay
reaction(IBD)
Determine the
neutrino mass
hierarchy

4. Detector Construction
Geometry Overview
Current Geometry Management Scheme
Geometry is designed to describe detector details and to provide consistent detector information for all applications
Text file
Geant4
Detector Construction
GDML file
Geometry
Service
Root
Interface
Geant4
Simulation
ROOT Geo (Object) file
Simulation Data file
Calibration
Recon-struction
Event
Display
Analysis

5. Geometry Data Generation
Geom Raw Data
Text file
Source code construction
Geant4
Detector Construction
Geom GDML Data
GDML file
Geant4
Simulation
ROOT Geo (Object) file
Geom ROOT Data
Simulation Data file

6. Identifier Numbering for each specific unit in all sub detectors
Mapping Identifier in offline
with 32 bits unsigned integer
CentralDetector, WaterPool and
TopTracker are ready

7. Geometry Service Construct every unique unit (PhysicalNode)
Mapping Identifier with units
Organize detector hierarchy
Provide functions for users
Application interfaces
parameters
txt file
Identifier
Geometry
Service
Root
Interface
ROOT Geo (Object) file
Simulation
Calibration
Recon-struction
Event
Display
Analysis

8. CentralDetector Measures the reactor neutrino signal
CenteralDetector Geometry can provide Detector information
AcrylicBall
Chimney
By some useful functions
CdGeom::getCdBallRmax()
CdGeom::getCdBallRmin()
CdGeom::getCdChimneyRmax()
...
AcrylicBall

9. CentralDetector PMTs CenteralDetector Geometry can get the information
of PMT (20inch & 3inch)
Shape, Materials, ...
Postion, Rotation
Theta, Phi, Layer, Azimuth
...
To print out each PMT's
center and direction
all PMTs

10. Other infomation Users can easily retrieve more information
Volume materials
Dimensions and boundary of a detector unit
A single line function to judge whether a point is inside a volume or not
Coordinate transformation
A single line function to transform coordinates between local and global coordiante or any level in between the geometry hierarchy …

11. WaterPool
Shield from natural radioactivity from the surrounding rock and air; detect the Cherenkov lights, acting as a veto detector
WpGeom can get PMT information
Postion
Direction
...
WpGeom can also get waterpool
information
Radius
Height
More information to be defined by users

12. TopTracker A muon veto detector to measure the muon tracks
TtGeom can provide strips information
Position
Dimensions
...
More information retrieved by users
To print out each unit's information

13. Geometry Service Requirements
Accurate
All detector information
Consistent
A single source of detector description shared by all applications
Flexible
Different geometry versions co-exist and are well managed in the software
Dynamic change of detector geometry over time
User-friendly
Easy read, modification, use
...

14. Parameter Management
The problem in current offline code: parameters in many different places of packages
The same parameters could be assigned different values and make conflicts;
Difficult for users to find
and modify the data they
want to change;
We need a better way to manage the parameters
The plan is to move all parameters into the Geometry Service, to make it the only source of data
Hard coded para. in SIM, RECO, …
Optical para. in prop., algo., *.icc, …
Geom, Material, Opt data in DetConstruction
PMT positions in SIM csv files
Geometry Service

15. Primary Data The primary data can be defined in the following formats:
Keyword Value
The primary data will be
The original data in resource repository
Simple (“raw” data, not after calculation)
Independent (non-redundancy)

16. Parameter Management Class
Design the primary geometry classes for
Each sub-system;
Different type of data;
User defined data;
Initialize and Retrieve
initialized at the beginning
of the geometry service
accessible with functions
CdGeomPrim::
CdOpticalPrim::
WpGeomPrim::
CdGeomPrim::
Initialize(){ SetOuterR(); }
GetInnerR()
GetOuterR()

17. Data Flow
A set of standard primary and secondary data need to be provided
Primary data
Applications
Geometry Service
Init
Functions
Secondary data
Derived
The secondary data
Derived from primary data
Could be GDML, XML, .icc, root
Provide more detailed geometry data information

18. Summary JUNO geometry service has been developed
The definition of identifiers has been proposed
CentralDetector and WaterPool work well
Geometry of TopTracker to be improved
Complete geometry parameter management

19. Thanks!