** Newly processed dataset  ** 

new discrimination parameter:
  * For selecting the <sup>152</sup>Gd alpha decay events: nSigmaBetaGamma < -3 ;  \\
  * For selecting the high energetic alpha peaks: Chi2 < 0.004 && nSigmaBetaGamma < -4.5   \\

As an example, pile-up events are seen below:
^  Pileup events with Chi2 > 0.004  ^
|  {{:gagg-nd:pileup.png?600|}}  |


** 1.) <sup>147</sup>Sm contamination (Q_alpha = 2311 keV) **
  * Identify the two peaks so we might improve the calibration curve and extract the contamination value  \\
  * Fit the alpha peak with a double Gaussian function (see below);  \\
  * Fitting results: Gaus1_mean: 9482.44, Gaus1_sigma: 341.22; Gaus2_mean: 9658.52, Gaus2_sigma: 427.95; chis/ndf = 1.33   \\
  * Problem: the mean values are not consistent with the calibration scale

^  Fitting the low energy alpha peak with a double Gaussian function  ^
|  {{:gagg-nd:gd_peak_fitting.png?600|}}  |


**2.) Extract events number from the two alpha triplets **
  * Convert the number of events to the specific activity (mBq/kg) for the contamination values;
  * Starting from the possible highest energy, namely <sup>219</sup>Rn -> <sup>215</sup>Po, and then trace back to <sup>223</sup>Ra -> <sup>219</sup>Rn (see below) ;  
  * Remove the previous triplet events, and look for the <sup>220</sup>Rn -> <sup>216</sup>Po (see below), and trace back to <sup>224</sup>Ra -> <sup>220</sup>Rn  \\

^    ^  Events number ^  Previous (L.) ^ Previous (S.) ^
| <sup>223</sup>Ra -> <sup>219</sup>Rn  |4135| 2481 | 2650 |
| <sup>219</sup>Rn -> <sup>215</sup>Po  |4961| 3174 | 2650 |
| <sup>224</sup>Ra -> <sup>220</sup>Rn  |6404| 9828 | 7908 |
| <sup>220</sup>Rn -> <sup>216</sup>Po  |10160| 9869 | 7908 |

Note that the Previous (S.) is taken from entries for the Gaussian fit.

^  <sup>223</sup>Ra -> <sup>219</sup>Rn delayed coincidence  ^
|  {{:gagg-nd:ra_rn_u.png?600|}}  |

^  <sup>220</sup>Rn -> <sup>216</sup>Po delayed coincidence  ^
|  {{:gagg-nd:rn_po_th.png?600|}}  |

^  <sup>224</sup>Ra -> <sup>220</sup>Rn delayed coincidence  ^
|  {{:gagg-nd:ra_rn_th.png?600|}}  |


**3.) Search for the <sup>222</sup>Rn -> <sup>218</sup>Po decays of the <sup>238</sup>U decay chain**

^   ^  Q-value [keV]  ^  Energy [keV] ^ T<sub>1/2</sub> ^
| <sup>222</sup>Rn  |  5590  |  5490 | 3.8 d|
| <sup>218</sup>Po  |  6115  |  6002 | 3.1min|
 
  * Firstly, apply the coincident cuts and remove the two triplet events;  \\
  * Then, select the first events in the range of (28000, 34000) and the second events of (34000, 38000);  \\
  * Fit the distribution of the time difference between two consecutive events, and got another value instead of 3.1 min; \\
  * Check the "Integral vs Time difference" 2D plot (an example seen below), which is flat; \\
  * Conclusion: the signal is not found

^  The integral of the first event versus the time difference   ^
|   {{:gagg-nd:rn_po_238u.png?600|}}  |


**4.) Search for the <sup>214</sup>Bi -> <sup>214</sup>Po decays of the <sup>238</sup>U decay chain**

^   ^  Q-value [keV]  ^  Decay mode ^ T<sub>1/2</sub> ^
| <sup>214</sup>Bi  |  3267  |  β(99.98%) | 19.9 min|
| <sup>214</sup>Po  |  7833  |  α | 164 us|
 
  * Firstly, apply the coincident cut and remove the 7526 keV alpha events;  \\
  * Select beta events in the energy range of (50000, 90000) with the nSigmaBetaGamma (0, 4.5);
  * Check the "Integral vs Time difference" 2D plot (an example seen below)
  
^  The integral of the second event (α) versus the time difference   ^
|   {{:gagg-nd:bi_po_238u.png?600|}}  |

**5.) Search for the <sup>212</sup>Bi -> <sup>208</sup>Tl decays of the <sup>232</sup>Th decay chain**|
^   ^  Q-value [keV]  ^  Decay mode ^ T<sub>1/2</sub> ^
| <sup>212</sup>Bi  | 6207   | α | 61 min|
| <sup>208</sup>Tl  |  1800+E<sub>γ</sub>  |  β+γ | 3.1 min|