Add Time-correlated single photon count (TCSPC)

[AsaphHall]

The goal of this Issue is to add tcspc to the ontology

[AsaphHall]

Changes that have been made so far (29.08.2024), * = 10.09.2024

Participating Devices:

• Excitation Source
• Detector
• timing electronics
• excitation filter
• emission filter
• neutral density filter

Excitation Source parameter:

• power
• repitition rate
• pulse width
• wavelength

Timing Electronics parameter:

• bin size
• sync input level
• edge (not implemented yet)

Detector parameter:

• dead time
• rise time*
• bandwidth*

TCSPC parameter:

• excitation laser power
• repitition rate
• pulse width
• count rate
• average count rate
• arrival time
• sync input level
• sync input level setting datum
• bin size
• bin size setting datum
• spot size
• neutral density filter
• excitation filter
• emission filter -stopping criterion -integration time

[AsaphHall]

A first look at the resulting graph

[felix-laufer]

Hey, I got feedback from two colleagues:

First one said that detector temperature could be added.

Second response:

• excitation source Bandwidth (nm)
• Excitation Type (laser, LED, laser + monochromator)... although this is rather optional.
• detector Bandwidth (nm). As an example, our TCSPC has a monochromator in the detection and selects the wavelength. Some do this with filters (excitation filter on the side) but the cleanest way is to use both.
• Rise-time at the detector. Or the general instrument response function (which, strictly speaking, does not only depend on the detector).
• Max count rate for the detector.
• Type of detector, i.e. photomultiplier, avalanche photodiode
• Stop criterion in general for a measurement, i.e. was the measurement stopped after 10 minutes or because 10,000 counts were reached or because 10,000 laser shots were made.

Neutral Density Filter can be used in both Excitation and Detection, this should be specified. Whereby it is somehow redundant in Excitation because you have the power in it. In Detection, it would also be redundant if you have the count rate in it.

Possibly also the name/type of the device with which the measurement is made. If it is a commercial device, this can help a lot with the classification.

Excitation laser power (usually mW) and excitation spot size (usually cm2) together give the excitation intensity (W/cm2). The intensity is usually more interesting for PV

[AsaphHall]

Thank you for the feedback Felix.

I´ve tried to implement the mentioned points and this is the revised graph. I did not yet include the excitation type because i havent implemented instances into the ontology (which can easily be included into a Nomad schema/database later on without it being part of the ontology). The ND-Filter is separated in excitation- and emission ND-Filters (the picture doesnt display that.) The picture is quite packed but the software doesnt allow me to add or remove single entities.

[MaximSimmonds-HZB]

Hi there! I just saw this and will add some comments, but all in all I think it looks good. " Rise-time at the detector. Or the general instrument response function (which, strictly speaking, does not only depend on the detector). The response function is usually very important to measure. It actually is a measurement itself, and has to be considered in cases where your material is not very good.

Neutral Density Filter can be used in both Excitation and Detection, this should be specified. Whereby it is somehow redundant in Excitation because you have the power in it. In Detection, it would also be redundant if you have the count rate in it. Maybe I am wrong, but I think we need to know how much were filtering. Indeed if your count rate goes up by some amount, is it because you changed filter or because your next sample is "better"? Hard to know without having the detection filtering noted down

Excitation laser power (usually mW) and excitation spot size (usually cm2) together give the excitation intensity (W/cm2). The intensity is usually more interesting for PV. Agreed, but it is always good to know what was actually measured, a local spot of a few um or cm? This is why the spotsize needed "

Concerning the timing electronics, I think that "sync channel level", "signal channel level", "signal channel edge" are missing. There is usually a delay associated with each channel, but I dont know if one could simply define it as one number (sum of both delays or something like that).

One question I do have left: NOMAD Camels, might have been working on a similar approach, as they also save setup related data in a FAIR manner. Did they work on such ontology?

[AsaphHall]

Thank you Maxim. This is the Graph after the feedback has been implemented.