[Gate-users] delayed event

[Marcin Balcerzyk]

Dear Eunsin.

 

The best way for me is to make a short (and low event number) simulation and
enable ascii output. Users Manual describes columns headings and meaning
depending on your geometry (by no means easy numbering scheme). One of the
principal characteristics is, as you write, eventID. If for a detected
coincidence eventIDs are not the same, and timestamp difference fits within
your coincidence window time, that means that they are random - that is they
are detected in the same coincidence window time (usually a few ns). For
delayed events you have to define new coincidenceSorter. In benchmarkPET in
digitizer.mac (Gate 5) there are lines to define it:

 

/gate/digitizer/name delay

/gate/digitizer/insert coincidenceSorter

/gate/digitizer/delay/setWindow 120. ns

/gate/digitizer/delay/setOffset 500. ns

/gate/digitizer/delay/MultiplesPolicy  takeWinnerOfGoods

 

Then looking at timestamps of each single forming coincidence (best in ascii
output initially), you would see that for eventID different in the case
above for more than 500 ns, the coincidences would be delayed. I think
setOffset value cannot be less than 100.0 ns. 

 

To analyze larger files, I would look at benchmarkPET.C and see how random
events are counted, and add a few lines of code for root to analyze delays.
If you have already run the benchmarkPET.mac, you have the delayed
coincidences simulated in benchmarkPET.root fiel and can have a look how
many are there. I think that delay coincidence sorter would contain only
delayed events. 

 

Kind regards

 

Marcin Balcerzyk

Universidad of Sevilla, Spain.

 

 

Message: 1

Date: Tue, 6 Jul 2010 13:53:29 -0400

From: Eunsin Lee <eunsin at mail.med.upenn.edu>

Subject: [Gate-users] delayed event

To: gate-users at lists.opengatecollaboration.org

Message-ID: <AB460B71-F675-49C3-9CF2-39FC719CE489 at mail.med.upenn.edu>

Content-Type: text/plain; charset=us-ascii

 

Dear GATE users,

 

In Gate root output there is a "delay" tree. Are these events are delayed
events?

 

Also in "Coincidences" tree, there are some events having different eventID
numbers, which is defined as random coincidence event in Gate. Aren't these
delayed events either?

 

Basically I want to tell prompt events from delayed events. How can I do
this in GATE?

 

Thanks so much in advance,

Eunsin