URL: https://www.desy.de/school/school_lab/zeuthen_site/cosmic_particles/glossar/@@siteview

## Breadcrumb Navigation

# Glossar

# S

## Scintillator

The transparency enables to guide the light to a photo sensor (PMT or MPPC) connected to the scintillator. More details can be found in the Wikipedia article.

The CosMO detectors consist of a plastics scintillator plate (20cm x 20cm x 1cm) where 9 fibers of 1mm diameter glued into the plate guide the light flash to the 3mm x 3mm surface of the multi pixel photon counter (MPPC).

The muon detectors at the “Polarstern”, the Neumayer III station and the Trigger Hodoscope use plastics scintillator plates (25cm x 25cm x 1.5cm) with 8 fibers of 1.5mm diameter which were originally produced for the L3-Cosmic experiment at CERN.

The LIDO experiment uses 12 liters of a liquid scintillator (EJ-321L, Eljen Technology). The main component is petroleum oil with additions of aromatic hydrocarbons and other components to produce the scintillation light.

## Silicon Photomultiplier

Details on SiPMs are given in the Wikipedia article. The SiPM used in the CosMO detectors has a sensitive surface of 3 mm x 3 mm. It is produced by Hamamatsu and called Multi-Pixel Photon Counter (MPPC, product type S10362-33-50C).

## Sine and Cosine Functions

The trigonometric functions sine and cosine and their squares describe mainly periodic processes or the dependence of a physical quantity on the angle. The general form of the sine function is: $f(x)=a\cdot \mathrm{sin}(bx+c)+d$

$a$ - stretch/ compression along the y-axis

$b$ - stretch/ compression along the x-axis. This parameter can be determined from the period $T$: $b=\frac{2\pi}{T}$

$c$ - shift along the x-axis. For a shift in positive x-direction, c is negative, for a shift in negative direction, c is positive.

$d$ - shift along the y-axis.

For example, the cosine^{2} function can be used to describe the zenith angle dependence of the muon flux with the CosMO mill. In Cosmic@Web, a fit function can be inserted directly into the corresponding diagram. The notation in the online analysis tool is as follows: p[0]+p[1]*cos(p[2]*x/180*pi)**2

Where **2 stands for the power. For example, x^{2} is represented as x**2.

The parameters p[0], p[1] and p[2] refer to the following properties:

p[0] - minimum of distribution

p[1] - maximum of distribution

p[2] - phase

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The adjacent diagram shows how to correctly read the parameters: