[gate-users] minSectorDifference

[Corinne J Groiselle]

Hi,

I have a question about the following command in the GATE digitizer 
because I am not sure I really understand what it means:

To exclude false coincidence coming from the same particle that 
scattered from a block to an adjacent block, a test is done on the 
proximity of the two blocks forming the coincidence event. By default, 
the coincidence is valid only if the difference in the block numbers is 
greater than two. This rejection can be adapted to a more specific 
analysis by using the command:

/gate/digitizer/Coincidences/minSectorDifference [number]

First of all, what does block mean? It's not one of the key words of any of the PET systems description (rsector, module, submodule, crystal, layer)?
Is it used for module or rsector depending on how the level of readout is defined with the command: /gate/digitizer/Singles/readout/setDepth 1 ?

a) In case we chose setDepth 1, does it mean that the coincidence will be kept only if rsectorID1 - rsectorID2 >= 2?
b) In case we chose setDepth 2, does it mean that the coincidence will be kept only if moduleID1 - moduleID2 >= 2?

If a), I understand that the rejection is radially dependent on the position of the block (there is only 1 rsector in the axial direction) but if b), the rejection is axially dependent on the position of the block (as the modules are numbered per rsector).

Could someone help me and tell me if I am correct of not?

Thanks a lot,

-- Corinne

------------------------------------------------------------------------
Corinne J. Groiselle, PhD
Research instructor

Division of Nuclear Medicine / Department of Radiology
University of Massachusetts Medical School
55 Lake Avenue North
Worcester, MA 01655
USA

_phone_: (508)-856-6123 - fax: (508)-856-4572
_e-mail_: Corinne.Groiselle at umassmed.edu
_professional homepage_: http://users.umassmed.edu/corinne.groiselle
_personal homepage_: http://corinne.groiselle.free.fr


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