Summer Research Program 2022
July 12th
Sebastián Ordoñez
Universidad Nacional de Colombia, COL
Supervisors: Agnieszka Leszczyńska and Alan Coleman
Study of the attenuation due to snow accumulation on IceTop tanks
Introduction
Motivation
- CR measurements with IceTop (IT) are affected by many environmental conditions
My work: Analyze the signal attenuation due to snow accumulating on the IT tanks for different air-shower particles.
Snow heights on top of IT tanks measured in Feb. 2012.
-
Snow height on top of the tanks increases on average by 20 cm every year.
- Significant impact on the measured signal and systematic uncertainties.
Introduction
Snow accumulation over the IceTop detector, measured in three different years: 2010, 2011, and
2012.
Status of the art
What we know
\boxed{S/S_{\text{nosnow}} = \exp\left(\frac{−x}{\lambda_{\text{eff}}}\right)}
- Some parameterizations have been used for the expected signal attenuated by snow:
- Applied to all tanks (average) > \(\lambda_{\text{eff}}\) for each year
- Energy, composition, or zenith angle of showers not included
"One size fits all"
Reality is a lot more complex, can we do it better? We can try.
- To be taken into account:
- \(e\) and \(\gamma\) experience snow attenuation much more so than \(\mu\).
- Factors: energy, signal size, zenith angle, and position with respect to the core.
First tests
Status
Please don't take these results too seriously!
Snow height: ~0.379m
Number of photoelectrons detected by DOMs in tank 36A
Next step!
Next step!
Simulation info
Status
-
Number of events: 100000
- Number of non-zero events: 60533
- Number of zero events: 39467*
- Tank: 36A
- Frame: IceTopMCHits - MCTopPESeriesMap
*Events in which only one DOM measured a PE where treated as zero events
- Simulation performed using g4-tankresponse: simple_injection.py
- GCD file: GeoCalibDetectorStatus_2012.56063_V1_OctSnow.i3.gz
- Details about the plots above:
Next steps
Outlook
- Check the source of the tails in the previous plots.
- Understand how the hits are obtained from the energy deposits.
- Run simulations for the whole phase space.
- Particles: muons, electrons, photons, hadrons, heavy things and more.
- Zenith angle
- Energy of injected particle
- Snow height
- Prepare method for sampling from these distributions
First presentation: IceCube internship
By Sebastian Ordoñez
