## 2 Characterisation Test Set-Up
### Angular Measurements Hardware Set-Up  
For the determination of the angular response of the FM, two sources with known activities, \({}^{241}\)Am and \({}^{137}\)Cs, were used. Due to the limited time with the FM, integrations with these sources at various angles were performed at the same time, with the two sources taped together. They were selected as the gamma-ray peaks from each were at sufficiently different energies so as to not interfere with each other. Figure 3 presents the hardware set-up used, where the spacecraft was mounted on a turntable with an attached moveable appendage. The turntable had a slip ring and interface printed circuit boards (PCBs), which facilitated powering and commanding the spacecraft via the UIU. The UIU provided an interface with a bench PSU to provide power for the spacecraft. It also provided the connection to the MCS on the laptop, which facilitated setting up the experiment and downlinking the data. This hardware was designed for attitude control and mission testing and utilised for GMOD characterisation. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Source No.** & **Source Name** & **Nuclide** & **Line Origin** & **Line Energy (keV)** & **Transition Probability** & **Half-Life (Years)** & **Activity (\(\updownarrow\)Ci)** \\ \hline
1 & Americium & \({}^{241}\)Am & \(\gamma\) & 59.40 * & 0.359 * & 432.2 & 11.16 \\ \hline
2 & Cobalt & \({}^{60}\)Co & \(\gamma\) & 1173.23 * & 0.998 * & 5.26 & 12.28 \\  & & \({}^{60}\)Co & \(\gamma\) & 1332.49 * & 0.999 * & 5.26 & 12.28 \\ \hline
3 & & \({}^{133}\)Ba & \(\gamma\) & 80.99 * & 0.901 * & 10.5 & 11.42 \\  & & \({}^{133}\)Ba & \(\gamma\) & 276.39 * & 0.075 * & 10.5 & 11.42 \\  & & \({}^{133}\)Ba & \(\gamma\) & 302.85 * & 0.191 * & 10.5 & 11.42 \\  & & \({}^{133}\)Ba & \(\gamma\) & 356.01 * & 0.636 * & 10.5 & 11.42 \\  & & \({}^{133}\)Ba & \(\gamma\) & 383.85 * & 0.091 * & 10.5 & 11.42 \\ \hline
4 & & \({}^{241}\)Am & \(\gamma\) & 59.40 * & 0.359 * & 432.2 & - \\  & & \({}^{137}\)Cs & Ba-137m & 661.66 * & 0.850 * & 30.17 & - \\  & & \({}^{60}\)Co & \(\gamma\) & 1173.23 * & 0.998 * & 5.26 & - \\  & & \({}^{60}\)Co & \(\gamma\) & 1332.49 * & 0.999 * & 5.26 & - \\ \hline
5 & Sodium & \({}^{22}\)Na & annihilation & 511 * & 1.798 * & 2.6 & 10 \\  & & \({}^{22}\)Na & \(\gamma\) & 1274.54 * & 0.999 * & 2.6 & 10 \\ \hline
6 & Caesium & \({}^{137}\)Cs & Ba-137m & 661.66 * & 0.850 * & 30.17 & 11.16 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Radioactive sources used for GMOD characterisation. The peak energies and transition probabilities for sources marked with an * are from [38] and those marked with \(\upuparrow\) are from [44]. The source activity for sources 1, 2, 3 and 6 are in \(\upmu\)Ci and quoted as of 12:00 GMT on 1 December 1979. The activity of source 5 is quoted as of 15 May 2013. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Source** & **Source Name** & **Location with Respect to** & **Location Relative to CoC** & **Int.** \\
**No.** & & **Centre of EIRSAT-1 (mm)** & **(mm)** & & **(Hours)** \\ \hline  & & X & Y & Z & X & Y & Z \\
1 & Americium & \(-10.57\) & \(-14.50\) & 298.5 & 0.00 & 0.00 & 234.6 & 12 \\
2 & Cobalt & \(-10.57\) & \(-14.50\) & 113.5 & 0.00 & 0.00 & 49.6 & 12 \\
3 & Barium & \(-10.57\) & \(-14.50\) & 216.5 & 0.00 & 0.00 & 152.6 & 12 \\
4 & Mixed Source & \(-10.57\) & \(-14.50\) & 113.5 & 0.00 & 0.00 & 49.6 & 12 \\
5 & Sodium & \(-10.57\) & \(-14.50\) & 252.5 & 0.00 & 0.00 & 188.6 & 12 \\
6 & Cesium & \(-10.57\) & 272.0 & 5.50 & 0.00 & \(-286.5\) & \(-58.4\) & 12 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Energy calibration source positions and the duration of spectral integrations. Sources 1–5 were placed above the \(+Z\) endcap of the spacecraft at various distances from the centre of the GMOD crystal (CoC). Source 6 was aligned with the CoC in X, placed 222 mm from the \(+Y\) face and 119 mm from the \(-Z\) face on the table.