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

  1. Check the source of the tails in the previous plots.
  2. Understand how the hits are obtained from the energy deposits.
  3. Run simulations for the whole phase space.
    • Particles: muons, electrons, photons, hadrons, heavy things and more.
    • Zenith angle
    • Energy of injected particle
    • Snow height
  4. Prepare method for sampling from these distributions