ELOG DESPEC

AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40

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Entry time:

Sat Mar 5 10:43:45 2022

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<h2>Tests performed</h2>

<ul>
	<li>After leaving overnight noticed the pulser was not fully inserted into aida09
	<ul>
		<li>Little change in rates observed in 9 but otherwise nothing else</li>
	</ul>
	</li>
	<li>Connected bias of aida02 (n+n ground) to aida06 (n+n ground) and likewise 4-8
	<ul>
		<li>No change observed in rates</li>
	</ul>
	</li>
	<li>Also tested covering the snout in light tight material
	<ul>
		<li>No Changes</li>
	</ul>
	</li>
	<li>Unplugged the system monitor from 6 and 8, no change</li>
	<li>Connected the snout to ground with copper tape
	<ul>
		<li>Rates became very unpredictable in the FEEs unsure if this was snout grounding related though</li>
		<li>Removed the ground and powercycled and rates restored to where previously</li>
	</ul>
	</li>
	<li>Changed the bias supply jumper inside to have the bias line connected to the rack ground
	<ul>
		<li>At the same time noticed that the ground cable connecting the adaptor board of aida06 to the FEE had become disconnected from the ring terminal
		<ul>
			<li>Recrimped and inserted again</li>
		</ul>
		</li>
		<li>Saw an improvment in the rates of the p+n strips and also the n+n strips - attachment 1</li>
		<li>Pulser widths however larger than yesterday</li>
	</ul>
	</li>
</ul>

<h3>p+n width</h3>

<table border="1" cellpadding="1" cellspacing="1" style="height:338px; width:253px">
	<thead>
		<tr>
			<th scope="col">FEE</th>
			<th scope="col">Width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>9</td>
			<td>118</td>
		</tr>
		<tr>
			<td>1</td>
			<td>88</td>
		</tr>
		<tr>
			<td>10</td>
			<td>75</td>
		</tr>
		<tr>
			<td>11</td>
			<td>77</td>
		</tr>
		<tr>
			<td>3</td>
			<td>67</td>
		</tr>
		<tr>
			<td>12</td>
			<td>66</td>
		</tr>
		<tr>
			<td>13</td>
			<td>96</td>
		</tr>
		<tr>
			<td>5</td>
			<td>89</td>
		</tr>
		<tr>
			<td>14</td>
			<td>107</td>
		</tr>
		<tr>
			<td>15</td>
			<td>93</td>
		</tr>
		<tr>
			<td>7</td>
			<td>118</td>
		</tr>
		<tr>
			<td>16</td>
			<td>87</td>
		</tr>
	</tbody>
</table>

<h3>n+n width</h3>

<ul>
	<li>Connected up entire pulser circuit to n+n FEEs</li>
</ul>

<table border="1" cellpadding="1" cellspacing="1" style="height:132px; width:253px">
	<thead>
		<tr>
			<th scope="col">FEE</th>
			<th scope="col">Width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>2</td>
			<td>428</td>
		</tr>
		<tr>
			<td>4</td>
			<td>N/A</td>
		</tr>
		<tr>
			<td>6</td>
			<td>428</td>
		</tr>
		<tr>
			<td>8</td>
			<td>343</td>
		</tr>
	</tbody>
</table>

<h2>Switching bias supply back</h2>

<ul>
	<li>because changes were made to the n+n ground, and the pulser circuit it was decided to go back and check the previous bias configuration with the module set in a floating configuration</li>
	<li>DAQ was then left overnight as had to leave to catch the bus</li>
	<li>Rates are observed to be back at their higher values - attachment 2</li>
	<li>n+n 1.8.L spectra - attachment 3</li>
	<li>p+n 1.8.L spectra - attachment 4</li>
</ul>

<h3>p+n widths</h3>

<table border="1" cellpadding="1" cellspacing="1" style="height:338px; width:301px">
	<thead>
		<tr>
			<th scope="col">FEE</th>
			<th scope="col">Wdith</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>9</td>
			<td>130</td>
		</tr>
		<tr>
			<td>1</td>
			<td>128</td>
		</tr>
		<tr>
			<td>10</td>
			<td>75</td>
		</tr>
		<tr>
			<td>11</td>
			<td>78</td>
		</tr>
		<tr>
			<td>3</td>
			<td>71</td>
		</tr>
		<tr>
			<td>12</td>
			<td>71</td>
		</tr>
		<tr>
			<td>13</td>
			<td>96</td>
		</tr>
		<tr>
			<td>5</td>
			<td>85</td>
		</tr>
		<tr>
			<td>14</td>
			<td>110</td>
		</tr>
		<tr>
			<td>15</td>
			<td>99</td>
		</tr>
		<tr>
			<td>7</td>
			<td>123 Dbl</td>
		</tr>
		<tr>
			<td>16</td>
			<td>92</td>
		</tr>
	</tbody>
</table>

<h3>n+n widths</h3>

<table border="1" cellpadding="1" cellspacing="1" style="height:132px; width:298px">
	<thead>
		<tr>
			<th scope="col">FEE</th>
			<th scope="col">width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>2</td>
			<td>56</td>
		</tr>
		<tr>
			<td>4</td>
			<td>983</td>
		</tr>
		<tr>
			<td>6</td>
			<td>523</td>
		</tr>
		<tr>
			<td>8</td>
			<td>358</td>
		</tr>
	</tbody>
</table>

<ul>
	<li>The results show no improvment to slightly worse performance so will go back to having the bias module grounded internally and check the previous conclusions hold before making further changes</li>
</ul>

<h2>Return to grounded bias module</h2>

<h3>Widths</h3>

<table border="1" cellpadding="1" cellspacing="1" style="height:377px; width:503px">
	<thead>
		<tr>
			<th scope="col">FEE</th>
			<th scope="col">Width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>9</td>
			<td>106</td>
		</tr>
		<tr>
			<td>1</td>
			<td>79</td>
		</tr>
		<tr>
			<td>10</td>
			<td>72</td>
		</tr>
		<tr>
			<td>11</td>
			<td>78</td>
		</tr>
		<tr>
			<td>3</td>
			<td>70</td>
		</tr>
		<tr>
			<td>12</td>
			<td>73</td>
		</tr>
		<tr>
			<td>13</td>
			<td>102</td>
		</tr>
		<tr>
			<td>5</td>
			<td>112</td>
		</tr>
		<tr>
			<td>14</td>
			<td>105</td>
		</tr>
		<tr>
			<td>15</td>
			<td>110</td>
		</tr>
		<tr>
			<td>7</td>
			<td>131</td>
		</tr>
		<tr>
			<td>16</td>
			<td>104</td>
		</tr>
	</tbody>
</table>

<table border="1" cellpadding="1" cellspacing="1" style="width:500px">
	<thead>
		<tr>
			<th scope="col">FEE</th>
			<th scope="col">Width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>2</td>
			<td>-</td>
		</tr>
		<tr>
			<td>4</td>
			<td>298</td>
		</tr>
		<tr>
			<td>6-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>8</td>
			<td>278</td>
		</tr>
	</tbody>
</table>

<ul>
	<li>Don&#39;t see a pulser peak in 4 or 2</li>
	<li>Will replace cable between 4 and 2 and 2 and 6</li>
	<li>Statistics at 0x64 with pulser on - atachment 5</li>
	<li>Now see peaks - attachment 6</li>
	<li>Statistics at 0xa - attachment 7</li>
</ul>

<table border="1" cellpadding="1" cellspacing="1" style="width:500px">
	<thead>
		<tr>
			<th scope="col">FEE</th>
			<th scope="col">Width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>2</td>
			<td>284</td>
		</tr>
		<tr>
			<td>4</td>
			<td>1089 (Triple)</td>
		</tr>
		<tr>
			<td>6</td>
			<td>371</td>
		</tr>
		<tr>
			<td>8</td>
			<td>318</td>
		</tr>
	</tbody>
</table>

<h3>With the grounded bias in place in the module move the braid cable to the frame rather than being connected to bias line</h3>

<ul>
	<li>Still observe a triple peak in 4 and have worse perfromance in 2 and no improvement in p+n</li>
	<li>0x64 stats - attachment 7</li>
	<li>0xa statistics - attachment 8</li>
	<li>p+n 1.8.L - attachment 9</li>
	<li>p+n waveform - attachment 10</li>
	<li>n+n waveform - attachment 11
	<ul>
		<li>Same high frequency component in both</li>
		<li>35 channel spacing corresponds to a frequency of ~1.4MHz</li>
	</ul>
	</li>
</ul>

<table border="1" cellpadding="1" cellspacing="1" style="width:500px">
	<thead>
		<tr>
			<th scope="col">FEE p+n</th>
			<th scope="col">Width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>9</td>
			<td>109</td>
		</tr>
		<tr>
			<td>1</td>
			<td>118</td>
		</tr>
		<tr>
			<td>10</td>
			<td>78</td>
		</tr>
		<tr>
			<td>11</td>
			<td>80</td>
		</tr>
		<tr>
			<td>3</td>
			<td>70</td>
		</tr>
		<tr>
			<td>12</td>
			<td>73</td>
		</tr>
		<tr>
			<td>13</td>
			<td>92</td>
		</tr>
		<tr>
			<td>5</td>
			<td>85</td>
		</tr>
		<tr>
			<td>14</td>
			<td>99</td>
		</tr>
		<tr>
			<td>15</td>
			<td>100</td>
		</tr>
		<tr>
			<td>7</td>
			<td>123</td>
		</tr>
		<tr>
			<td>16</td>
			<td>92</td>
		</tr>
	</tbody>
</table>

<table border="1" cellpadding="1" cellspacing="1" style="width:500px">
	<thead>
		<tr>
			<th scope="col">FEE n+n</th>
			<th scope="col">Width</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>2</td>
			<td>531</td>
		</tr>
		<tr>
			<td>4</td>
			<td>1185 (Triple)</td>
		</tr>
		<tr>
			<td>6</td>
			<td>536</td>
		</tr>
		<tr>
			<td>8</td>
			<td>376</td>
		</tr>
	</tbody>
</table>

<h2>Next tests</h2>

<ul>
	<li>Returned braid to FEE 4 and 8
	<ul>
		<li>Recovered earlier rates and performance</li>
	</ul>
	</li>
	<li>Re-added the ground cable to the snout
	<ul>
		<li>Much worse noise performance across all FEEs</li>
		<li>p+n rates in 200k</li>
	</ul>
	</li>
	<li>Removed the ground from the snout
	<ul>
		<li>Got really good rates originally - attachment 12</li>
		<li>Noticed 1 and 5 failed ADC calibration</li>
		<li>Calibrated them and there rates increased massively - attachment 13</li>
	</ul>
	</li>
	<li>Notice that the pulser peak in FEE2 and 6 keeps dropping out
	<ul>
		<li>As the cables have been changed multiple times thought it could be that an adaptor board was broken</li>
		<li>4 seemed the most likely suspect with its high rates and triple peaks</li>
		<li>Replaced the adaptor board with one missing an outer ERNI pin (PIN doesn&#39;t interface with the FEE so didn&#39;t see any issues)</li>
		<li>Pulser peaks were still muissing</li>
		<li>Issue could be then with adaptor board 2 possibly</li>
	</ul>
	</li>
</ul>

<h1>Conclusions</h1>

<ul>
	<li>Rates on the FEEs are in a better place now than they were at the start of the week
	<ul>
		<li>p+n in particular have shown a large amount of improvement</li>
	</ul>
	</li>
	<li>There are still however issues with the n+n FEEs</li>
	<li>I think there is likely an issue with one of the adaptor boards
	<ul>
		<li>Possible aida02 at the pulser connection point</li>
		<li>Could explain the triple peaking in aida04 and the pulser issues with aida02 and aida06 dropping out.</li>
		<li>Would recomend swapping out aida02 as a test next week</li>
	</ul>
	</li>
	<li>Other possible issues coiuld be the clingfilm around the cables has torn and we are grounding the cables to the inside of the snout
	<ul>
		<li>Nic would like to use something other than clingfilm in future</li>
		<li>One suggestion would be mylar which could be held in place with strips of double sided tape</li>
		<li>This would make the cables less likely to stick to each other which is an issue with the tightness of the snout</li>
	</ul>
	</li>
	<li>Could also try removing LK3 from FEE3 and 7 leaving the PCB ground floating</li>
	<li>I am at a slight loss of what else to try</li>
</ul>

<ul>
	<li>I have left the daq running at 0x64 overnight to check for alphas</li>
	<li>Histograms and statistics zeroed</li>
</ul>

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