4 of 90

LIME - Detector and Data

50 L & 50 cm drift gaseous TPC
He:CF4, 60:40, 1 Atm (910 mbar), 293 K
4 PMTs + 1 sCMOS camera
One event =

1 CMOS pic: R_Δt = 300 ms
X PMT WFs = N_triggers * N_PMTs * N_digitiz

R_Δt = 1.3 ns & 4 ns

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

5 of 90

LIME - Detector and Data

50 L & 50 cm drift gaseous TPC
He:CF4, 60:40, 1 Atm (910 mbar), 293 K
4 PMTs + 1 sCMOS camera
One event =

1 CMOS pic: R_Δt = 300 ms
X PMT WFs = N_triggers * N_PMTs * N_digitiz

R_Δt = 1.3 ns & 4 ns

The information needs to be matched!

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

6 of 90

3D Event Reconstruction

One-to-One association

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

7 of 90

To fully reconstruct the information of one event we need to merge the CMOS and PMTs information.

We developed a 1-to-1 association to merge the CMOS clusters to PMT triggers.

3D Events - One-to-One association

Light seen by each PMT depends on their relative positions.

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

8 of 90

To fully reconstruct the information of one event we need to merge the CMOS and PMTs information.

We developed a 1-to-1 association to merge the CMOS clusters to PMT triggers.

3D Events - One-to-One association

Light seen by each PMT depends on their relative positions.

We apply a multi-variable Bayesian fit in a time window by integrating the charge ⇒ We retrieve (x, y, L) information

Alphas

⁵⁵Fe

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

9 of 90

To fully reconstruct the information of one event we need to merge the CMOS and PMTs information.

We developed a 1-to-1 association to merge the CMOS clusters to PMT triggers.

3D Events - One-to-One association

With (x, y, L) retrieved, we compare with CMOS clusters and assign them through the closest neighbor.

Cosmics/ long ERs

⁵⁵Fe spots

Alphas

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

10 of 90

To fully reconstruct the information of one event we need to merge the CMOS and PMTs information.

We developed a 1-to-1 association to merge the CMOS clusters to PMT triggers.

3D Events - One-to-One association

The final goal is to implement this technique at the detector front-end level. The efficiencies are promising! (The reference is the 33x33cm² GEM plane)

Performances for�– ⁵⁵Fe (spot-like) events:

X_std/Y_std ~ 1.6 cm

– Alphas:

X_std/Y_std ~ 2,3 cm

Optimization undergoing concerning effects like saturation, lens barreling, gain inter-calibration, etc.

With (x, y, L) retrieved, we compare with CMOS clusters and assign them through the closest neighbor.

Cosmics/ long ERs

⁵⁵Fe spots

Alphas

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

11 of 90

3D Event Reconstruction

CMOS analysis

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

12 of 90

The analysis of the CMOS images starts with a directional iDBSCAN algorithm which clusters groups of pixels belonging to the same ionization event.

For PID, each cluster can be selected through its: light integral, length, slimness, photon density, dE/dx, etc.

3D Events - CMOS analysis

Directional iDBSCAN to detect cosmic-ray tracks for the CYGNO experiment - IOPscience

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

13 of 90

The analysis of the CMOS images starts with a directional iDBSCAN algorithm which clusters groups of pixels belonging to the same ionization event.

For PID, each cluster can be selected through its: light integral, length, slimness, photon density, dE/dx, etc.

3D Events - CMOS analysis

A second layer analysis is used to determine other more dedicated variables such as 2D direction

Directional iDBSCAN to detect cosmic-ray tracks for the CYGNO experiment - IOPscience

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

14 of 90

The analysis of the CMOS images starts with a directional iDBSCAN algorithm which clusters groups of pixels belonging to the same ionization event.

For PID, each cluster can be selected through its: light integral, length, slimness, photon density, dE/dx, etc.

3D Events - CMOS analysis

A second layer analysis is used to determine other more dedicated variables such as 2D direction

Reconstructed info here:

• ΔXY • X-Y angle (𝛟) • 2D direction

Directional iDBSCAN to detect cosmic-ray tracks for the CYGNO experiment - IOPscience

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

15 of 90

3D Event Reconstruction

PMT �analysis

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

16 of 90

The PMTs gives us information regarding the longitudinal coordinate Z, and allows us to close the 3D geometry

3D Events - PMT analysis

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

17 of 90

The PMTs gives us information regarding the longitudinal coordinate Z, and allows us to close the 3D geometry

3D Events - PMT analysis

Time-over-Threshold ⇒ Traveled Z

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

18 of 90

The PMTs gives us information regarding the longitudinal coordinate Z, and allows us to close the 3D geometry

3D Events - PMT analysis

Time-over-Threshold ⇒ Traveled Z
Highest integral ⇒ XY Quadrant

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

19 of 90

The PMTs gives us information regarding the longitudinal coordinate Z, and allows us to close the 3D geometry

3D Events - PMT analysis

Time-over-Threshold ⇒ Traveled Z
Highest integral ⇒ XY Quadrant
Bragg peak position ⇒ Moving towards GEMs or cathode

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

20 of 90

The PMTs gives us information regarding the longitudinal coordinate Z, and allows us to close the 3D geometry

3D Events - PMT analysis

Time-over-Threshold ⇒ Traveled Z
Highest integral ⇒ XY Quadrant
Bragg peak position ⇒ Moving towards GEMs or cathode

*Additionaly, the alpha PID is performed at this stage, using these and others variables.

Non-alphas are discarded.

Optimized?

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

21 of 90

The PMTs gives us information regarding the longitudinal coordinate Z, and allows us to close the 3D geometry

3D Events - PMT analysis

Time-over-Threshold ⇒ Traveled Z
Highest integral ⇒ XY Quadrant
Bragg peak position ⇒ Moving towards GEMs or cathode

Additional reconstructed info:

ΔZ
Sign of θ

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

22 of 90

The PMTs gives us information regarding the longitudinal coordinate Z, and allows us to close the 3D geometry

3D Events - PMT analysis

Time-over-Threshold ⇒ Traveled Z
Highest integral ⇒ XY Quadrant
Bragg peak position ⇒ Moving towards GEMs or cathode

Additional reconstructed info:

ΔZ + ΔXY = Z angle (theta)
Sign of θ + sign of 𝛟 = Head-tail

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

23 of 90

3D Event Reconstruction

Recent Improvements

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

24 of 90

When studying the distribution of the supposedly Rn alphas, two variables are important:

Absolute Z position + Angular distribution

3D Events - Absolute Z

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

25 of 90

When studying the distribution of the supposedly Rn alphas, two variables are important:

Absolute Z position + Angular distribution

The absolute Z position, or fiducialization, is determined by fitting the track distribution of light in the orthogonal direction ⇒ “Transverse profile”

3D Events - Absolute Z

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

26 of 90

When studying the distribution of the supposedly Rn alphas, two variables are important:

Absolute Z position + Angular distribution

The absolute Z position, or fiducialization, is determined by fitting the track distribution of light in the orthogonal direction ⇒ “Transverse profile”

https://www.sciencedirect.com/science/article/pii/S0168900215003320

https://www.sciencedirect.com/science/article/pii/S0168900221001935

3D Events - Absolute Z

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

27 of 90

When studying the distribution of the supposedly Rn alphas, two variables are important:

Absolute Z position + Angular distribution

The absolute Z position, or fiducialization, is determined by fitting the track distribution of light in the orthogonal direction ⇒ “Transverse profile”

https://www.sciencedirect.com/science/article/pii/S0168900215003320

https://www.sciencedirect.com/science/article/pii/S0168900221001935

I used LEMOn values. Clear offset since LIME is 50 cm.
I also tried Roque’s result ⇒ Huge uncertainty, and similar result
Usable to hint absolute Z position

3D Events - Absolute Z

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

28 of 90

3D Events - Cutted tracks

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

29 of 90

Improvement of 3D Reco

Sensor-cut alphas removal ⇒ Cleans low energy tail
This can affect the effectiveness of the directionality code, thus decreasing our head-tail capabilities.

3D Events - Cutted tracks

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

30 of 90

Improvement of 3D Reco

Sensor-cut alphas removal ⇒ Cleans low energy tail
This can affect the effectiveness of the directionality code, thus decreasing our head-tail capabilities.

Noisy band cut on the reconstruction code

Accounts for 15% of events

3D Events - Cutted tracks

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

31 of 90

Improvement of 3D Reco

Sensor-cut alphas removal ⇒ Cleans low energy tail
This can affect the effectiveness of the directionality code, thus decreasing our head-tail capabilities.

CMOS sensor active row cut

Noisy band cut on the reconstruction code

Accounts for 15% of events

Requires 3D match
6% of events

3D Events - Cutted tracks

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

32 of 90

3D Event Reconstruction

Dual sensor 3D analysis

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

33 of 90

3D Events - 3D analysis

With the sensors’ individual and merged information, we can now fully analyze the events and perform particle ID, reject backgrounds from known sources, and fully characterize the 3D direction ⇒ Directionality

The first studies were focused on Alpha Particles

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

34 of 90

Alpha studies

The Rn case study

What I have been showing…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

35 of 90

When comparing our data vs. simulation, we found discrepancies, possibility attributed to ²²²Rn.

3D Events - The Rn study

2D alpha

length (mm)

What I have been showing…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

36 of 90

When comparing our data vs. simulation, we found discrepancies, possibility attributed to ²²²Rn.
The ²²²Rn decay chain produces 3 alphas in ~equilibrium. Due to their high energy, we are more sensitive to the length.

²²²Rn ⇒ 5.59 MeV ⇒ 4.3 cm
²¹⁸Po ⇒ 6.12 MeV ⇒ 5.0 cm
²¹⁴Po ⇒ 7.83 MeV ⇒ 7.3 cm

2D alpha

length (mm)

3D Events - The Rn study

What I have been showing…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

37 of 90

When comparing our data vs. simulation, we found discrepancies, possibility attributed to ²²²Rn.
The ²²²Rn decay chain produces 3 alphas in ~equilibrium. Due to their high energy, we are more sensitive to the length.

²²²Rn ⇒ 5.59 MeV ⇒ 4.3 cm
²¹⁸Po ⇒ 6.12 MeV ⇒ 5.0 cm
²¹⁴Po ⇒ 7.83 MeV ⇒ 7.3 cm

2D alpha

length (mm)

3D alpha

length (cm)

Preliminary

3D Events - The Rn study

What I have been showing…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

38 of 90

²²²Rn ⇒ 5.59 MeV ⇒ 4.3 cm
²¹⁸Po ⇒ 6.12 MeV ⇒ 5.0 cm
²¹⁴Po ⇒ 7.83 MeV ⇒ 7.3 cm

2D alpha

length (mm)

3D alpha

length (cm)

Fitted peaks:

4.43 cm
5.12 cm
7.29 cm

Very similar!

Preliminary

When comparing our data vs. simulation, we found discrepancies, possibility attributed to ²²²Rn.
The ²²²Rn decay chain produces 3 alphas in ~equilibrium. Due to their high energy, we are more sensitive to the length.

Additional resolution reassure us of the presence of Rn in the gas.

3D Events - The Rn study

What I have been showing…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

39 of 90

Geant4 simulation not compatible with measured nor “expected”

Measured MC ranges:

64.5
44.5
39.1

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

40 of 90

Alpha studies

Alpha range in LIME

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

41 of 90

But where do these ranges come from? Flaminia’s thesis? Geant4? SRIM?
We have seen previously that the alpha length could be slightly overestimated due to the “minimum signal possible”. ”Consistent” with the fact Geant4 shows smaller lengths…

Alphas - Alpha range in LIME

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

42 of 90

But where do these ranges come from? Flaminia’s thesis? Geant4? SRIM?
We have seen previously that the alpha length could be slightly overestimated due to the “minimum signal possible”. ”Consistent” with the fact Geant4 shows smaller lengths…

I tried to understand the origin of this… I checked and compared:

Davide Pinci’s values ⇒ Compatible with data, but no source (?)
Flaminia’s thesis ⇒ No final values in the thesis ⇒ “range tables by SRIM for our gas mixture”
CYGNO Simulation ⇒ Incompatible with data, consistent between simulators (Fiorina & Melba)
Theoretical calculation using NIST calculators ⇒ Approximated for He:CF4 starting from air ⇒ Inconsistent with everything.
SRIM ⇒ Supposedly the source of evertyhing
My 3D analysis (= data)

Alphas - Alpha range in LIME

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

43 of 90

I tried to make the new alpha digitization work to see if the difference in MC and data is recovered there.

(Thanks Melba for the alphas, and Giorgio & Piacentini for digi details)

Alphas - Digitization

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

44 of 90

I tried to make the new alpha digitization work to see if the difference in MC and data is recovered there.

(Thanks Melba for the alphas, and Giorgio & Piacentini for digi details)

Alphas - Digitization

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

45 of 90

I tried to make the new alpha digitization work to see if the difference in MC and data is recovered there.

(Thanks Melba for the alphas, and Giorgio & Piacentini for digi details)

Outcomes…

Lengths for the 3 Rn alphas are, on average:

61.6 ; 69.4; 97.9 mm

They are bigger than simulation ✅
But also much bigger than data* ❌

*Actually Pietro found encouraging results on these!

Alphas - Digitization

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

46 of 90

I tried to make the new alpha digitization work to see if the difference in MC and data is recovered there.

(Thanks Melba for the alphas, and Giorgio & Piacentini for digi details)

Outcomes…

Lengths for the 3 Rn alphas are, on average:

61.6 ; 69.4; 97.9 mm

They are bigger than simulation ✅
But also much bigger than data* ❌

Profile of digitized track not really Gaussian

Neither data, but hint for improvement!

Saturation UNDERSTANDING ?!

Digi not there to help me, but almost

Empirical explanation incoming

*Actually Pietro found encouraging results on these!

Alphas - Digitization

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

47 of 90

SRIM

SRIM needs two important inputs: stoichiometry of gas mixture and gas density. What’s the gas density of LIME?

Alphas - SRIM

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

48 of 90

SRIM

SRIM needs two important inputs: stoichiometry of gas mixture and gas density. What’s the gas density of LIME?

Theoretical: d = 1.4 kg/m³

Ranges calculated with this density, consistent with Geant4
Now we know SRIM works.

Alphas - SRIM

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

49 of 90

SRIM

SRIM needs two important inputs: stoichiometry of gas mixture and gas density. What’s the gas density of LIME?

Theoretical: d = 1.4 kg/m³

Ranges calculated with this density, consistent with Geant4
Now we know SRIM works.

But actually LIME has a density sensor, which in the dates ranges� of my analysis goes from:

density = [ 1.46 - 1.50 kg/m3]

Alphas - SRIM

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

50 of 90

SRIM

SRIM needs two important inputs: stoichiometry of gas mixture and gas density. What’s the gas density of LIME?

Theoretical: d = 1.4 kg/m³

Ranges calculated with this density, consistent with Geant4
Now we know SRIM works.

But actually LIME has a density sensor, which in the dates ranges� of my analysis goes from:

density = [ 1.46 - 1.50 kg/m3]
Using these values, I get these ranges. These will be the ones to be compared with!

Energy	Range (avg) ± Error (1/2*max diff)
5.49	37.37 ± 0.51
6.0	42.50 ± 0.58
7.69	62.14 ± 0.84

Alphas - SRIM

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

51 of 90

SRIM

SRIM needs two important inputs: stoichiometry of gas mixture and gas density. What’s the gas density of LIME?

Theoretical: d = 1.4 kg/m³

Ranges calculated with this density, consistent with Geant4
Now we know SRIM works.

But actually LIME has a density sensor, which in the dates ranges� of my analysis goes from:

density = [ 1.46 - 1.50 kg/m3]
Using these values, I get these ranges. These will be the ones to be compared with!

Energy	Range (avg) ± Error (1/2*max diff)
5.49	37.37 ± 0.51
6.0	42.50 ± 0.58
7.69	62.14 ± 0.84

Alphas - SRIM

*Flaminia wrote in her thesis the CYGNO gas mixture density is 1.53 kg/m³

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

52 of 90

Let’s re-start the discussion…

With correct energies & ranges

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

53 of 90

²²²Rn ⇒ 5.49 MeV ⇒ 3.74 cm
²¹⁸Po ⇒ 6.00 MeV ⇒ 4.25 cm
²¹⁴Po ⇒ 7.69 MeV ⇒ 6.21 cm

Fitted peaks:

4.43 cm
5.12 cm
7.29 cm

Similar!

Not consistent anymore! ⇒ Possible missing component

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

54 of 90

There’s a missing component not being account for: the minimum XYZ signal
I calculated the transverse and longitudinal diffusion from ⁵⁵Fe signals, and add the average to the expected ranges.
Since I don’t know the position of the event in Z à priori, I will take the mean value (step 3) to correct the 3D lengths.

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

55 of 90

There’s a missing component not being account for: the minimum XYZ signal
I calculated the transverse and longitudinal diffusion from ⁵⁵Fe signals, and add the average to the expected ranges.
Since I don’t know the position of the event in Z à priori, I will take the mean value (step 3) to correct the 3D lengths.

Minimum 3D length = 8.39 mm ± half of the maximum variation = 1.04mm

3D Events - The Rn study

Final result for the Minimum XY / Z: XY: 5.7mm Z: 3.95 mm
Longitudinal diffusion smaller than transverse ✅

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

56 of 90

There’s a missing component not being account for: the minimum XYZ signal
I calculated the transverse and longitudinal diffusion from ⁵⁵Fe signals, and add the average to the expected ranges.
Since I don’t know the position of the event in Z à priori, I will take the mean value (step 3) to correct the 3D lengths.

Minimum 3D length = 8.39 mm ± half of the maximum variation = 1.04mm

3D Events - The Rn study

Now the results are consistent!

No shady business!

Final result for the Minimum XY / Z: XY: 5.7mm Z: 3.95 mm
Longitudinal diffusion smaller than transverse ✅

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

57 of 90

But is it really Radon?

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

58 of 90

If I remove the contribution from the field rings…

Clear selection of events in the center (likely Radon)

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

59 of 90

If I remove the contribution from the field rings…

Clear selection of events in the center (likely Radon)

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

60 of 90

If I remove the contribution from the field rings…

Clear selection of events in the center (likely Radon)

3D Events - The Rn study

*I studied the area ratios (~50%, 25%), with assumptions of charged daughters, but no conclusions once we looked at the distribution in Z.

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

61 of 90

When studying the distribution of the supposedly Rn alphas, two variables are important:

Absolute Z position + Angular distribution

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

62 of 90

When studying the distribution of the supposedly Rn alphas, two variables are important:

Absolute Z position + Angular distribution

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

63 of 90

When studying the distribution of the supposedly Rn alphas, two variables are important:

Absolute Z position + Angular distribution

3D Events - The Rn study

Alphas emitted at higher Z at each step of the chain because the Rn daughters are emitted charged (mostly)

Thus why 7.69 MeV alpha is emitted mostly towards the GEMS (from the cathode). Seen also by DRIFT, MIMAC, and other

Alphas at ~4 cm length (²²²Rn) see a preferential emission towards the cathode instead, although it’s not clear why.
Remaining alphas at lower (< 4 cm) length are thought to come from the U/Th chains…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

64 of 90

If we look at the other peaks, at ~3.4 cm and ~6.1 cm, we can estimate their energies

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

65 of 90

If we look at the other peaks, at ~3.4 cm and ~6.1 cm, we can estimate their energies

3D Events - The Rn study

https://doi.org/10.1016/j.phpro.2014.12.022

DRIFT results

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

66 of 90

If we look at the other peaks, at ~3.4 cm and ~6.1 cm, we can estimate their energies

3D Events - The Rn study

https://doi.org/10.1016/j.phpro.2014.12.022

DRIFT results

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

67 of 90

If we look at the other peaks, at ~3.4 cm and ~6.1 cm, we can estimate their energies

3D Events - The Rn study

https://doi.org/10.1016/j.phpro.2014.12.022

DRIFT results

*The tails could be U alphas that lose part of energy in material.

*We also kind of see Po210 shoulder.

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

68 of 90

If we look at the other peaks, at ~3.4 cm and ~6.1 cm, we can estimate their energies

3D Events - The Rn study

And who is emitting all this Uranium?

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

69 of 90

If we look at the other peaks, at ~3.4 cm and ~6.1 cm, we can estimate their energies

3D Events - The Rn study

And who is emitting all this Uranium?

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

70 of 90

If we look at the other peaks, at ~3.4 cm and ~6.1 cm, we can estimate their energies

3D Events - The Rn study

The field rings!
Alphas emitted throughout all detector in Z
Mostly at the borders

Not surprising!

And who is emitting all this Uranium?

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

71 of 90

But what about the energy? Measurable?

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

72 of 90

First we need to select alphas with the same saturation:

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

73 of 90

First we need to select alphas with the same saturation:

Cuts on: absolute Z; Z angle (!); central region (only Rn alphas)

3D Events - The Rn study

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

74 of 90

First we need to select alphas with the same saturation:

Cuts on: absolute Z; Z angle (!); central region (only Rn alphas)

3D Events - The Rn study

Peaks clearly suggested a priori…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

75 of 90

3D Events - The Rn study

But if I look at the singular contributions…

First we need to select alphas with the same saturation:

Cuts on: absolute Z; Z angle (!); central region (only Rn alphas)

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

76 of 90

3D Events - The Rn study

But if I look at the singular contributions…

Comparing with “good” ⁵⁵Fe resolution published, it’s even compatible… stiamo 🏇

First we need to select alphas with the same saturation:

Cuts on: absolute Z; Z angle (!); central region (only Rn alphas)

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

77 of 90

Yesterday analysis…

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

78 of 90

Alphas - The profile shape

The alphas are not really Gaussian… they seem more triangular (!?) … also different from in NID…

Gaussian fit not really appropriate
Alphas strongly saturated

The study of the profile could help the study or understanding / modelling of the saturation with the help of digitization

Samuele suggested me to use the Transverse Profile distribution (histo) RMS

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

79 of 90

3D Events - The Rn study

Samuele suggested me to use the alpha profile RMS isntead of the (poorly calculated) sigma…

Profile Sigma

Profile RMS

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

80 of 90

3D Events - The Rn study

Samuele suggested me to use the alpha profile RMS isntead of the (poorly calculated) sigma…

Profile Sigma

Profile RMS

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

81 of 90

3D Events - The Rn study

Samuele suggested me to use the alpha profile RMS isntead of the (poorly calculated) sigma…

Profile Sigma

Profile RMS

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

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Gained much resolution! Rn alpha confirm!
Rn progeny drift towards cathode even more clear!
Is RMS (from PROFILE) a good measure of diffusion and subsequently absolute Z?
Maybe LIME is really 80 cm long (did you measure it?)

3D Events - The Rn study

Samuele suggested me to use the alpha profile RMS isntead of the (poorly calculated) sigma…

Profile Sigma

Profile RMS

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

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The merging of CMOS (X-Y) with PMT (Z) information is performed with a Bayesian fit.

Reconstructing ionization events in 3D greatly improves spatial resolution and our PID capabilities.

From the suspicion of the presence of Rn, the 3D analysis allows us to almost confirm its presence and, through its emission direction, its origin became more clear.

Other decay chains identified with this method
3D analysis is more efficient than energy analysis (better resolution)
Shape of the alpha cloud profile interesting ⇒ Relation to saturation and absolute Z

Currently paper on CMOS+PMT association, 3D reco and Rn lengths undergoing.

Conclusions - What has been done

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

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Studies on the application of the 3D analysis for NR and others.

The framework is there ⇒ Just need to PID different particles and analyze them

Improvements in the code

I’m lacking optimization of parameters, and there are a lot!

PMT simulation is paramount!

Implement the new version of BAT

And probably implement it at DAQ level 0

Alphas are cool, but what now?

Additional following paper on 3D results with discussion of the origin of the background? With possible comparison with MC?

We can still work together after I’m gone! ♥🏳

Conclusions - What should be done

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

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The CYGNO Project counts with the collaboration of several international researchers, coming from:

Thank you for �your attention!

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Backups

more details

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

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Alphas - Improvement of 3D reco

The CMOS sensor active row cut is checked using Piacentini’s formula. I use a 2 mm window for small variations.

bool cutted_frame = false;

double activeRow = 0, active_row_cm = 0;

double active_range_low = std::min(c_begin_Y, c_end_Y), active_range_high = std::max(c_begin_Y, c_end_Y);

double window_check = 0.2;

if (ttt_time > 184.4 && ttt_time < 300) {

active_row_cm = 36.; // inside Global exposure

std::cout << "--> This track is *NOT* cut by the sensor." << std::endl;

} else {

std::cout << "--> This track *COULD* be cut, let's check..." << std::endl;

if (ttt_time < 184.4) activeRow = 2304.0 - (2304.0 * (ttt_time / 184.4));

else if (ttt_time > 300.0) activeRow = 2304.0 - (2304.0 * ((ttt_time - 300.0) / 184.4));

active_row_cm = activeRow * granu;

if (active_row_cm > (active_range_low - window_check) && active_row_cm < (active_range_high + window_check)) {

std::cout << "--> This track *IS* cut by the sensor!" << std::endl;

cutted_frame = true;

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

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Alphas - Improvement of 3D reco

A cross-check is now performed in order to identify alphas where this happens.
The noisy cut band it’s easy to check, and I check if the track starts or end within 1 mm from the cuts:

// To ensure we consider the correct limits independently of the track direction

double active_range_low = std::min(c_begin_Y, c_end_Y);

double active_range_high = std::max(c_begin_Y, c_end_Y);

// 1 mm window to mitigate mismatch between pixel rows and cm position due to granularity

double window = 0.1; //millimiter

double noisy_Y_band_high = (2304. - 304.) * granu - window;

double noisy_Y_band_low = (0. + 250.) * granu + window;

if (active_range_high > noisy_Y_band_high || active_range_low < noisy_Y_band_low) {

std::cout << "--> This track *IS* cut by the noisy band cut in the reco." << std::endl;

cutted_track = true;

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024

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Alphas - Trans/Long Diffusion

I took about 20 calibration runs * 5 steps from batch6 of the alpha dataset.
I measure the total time and space length of the ⁵⁵Fe signal seen by the PMT and CMOS, respectively.
For the PMT ⇒ PMT_Avg_Events->Draw("pmt_peak_FullWidth>>hist_tw", "pmt_wf_sampling == 1024 && pmt_peak_Number == 1", "goff");
For the CMOS ⇒ Events->Draw("sc_length>>hist_sc_length", "sc_length < 200 && sc_rms > 6 && sc_tgausssigma > 0.5/0.152 && sc_tgausssigma/sc_lgausssigma > 0.7 && sc_width/sc_length > 0.7 && sqrt((sc_xmean-2304/2)**2 + (sc_ymean-2304/2)**2) < 800", "goff");
I perform a Gaussian fit for each step
I convert the mean to cm:

μ_new[cm] = μ[ADC] * time_to_cm = μ * (4./3.) * 5.471E-3
μ_new[cm] = μ[pixels] * granularity = μ * 0.0155

I plot the mean of the Gaussian (μ_new) as a function of the step position in cm
I fit these points with sqrt([0]*[0] + [1]*[1]*x)

David Marques

CYGNO Collaboration Meeting - Nov 27 - 29, 2024