Electron Gun - Revision history

EGun5214: /* Final Results */

2022-04-30T16:37:55Z

Final Results

← Older revision		Revision as of 16:37, 30 April 2022
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	The electron source, a filament, was also prepared by breaking a bulb. The glass was broken by lightly tapping the bulb with a metal hammer in a plastic bag. Broken glass fragments were then cleaned up.		The electron source, a filament, was also prepared by breaking a bulb. The glass was broken by lightly tapping the bulb with a metal hammer in a plastic bag. Broken glass fragments were then cleaned up.

	====~~Final Results~~====		====Photos====
	The 3 components and the filament were successfully prepared for the system.		The 3 components and the filament were successfully prepared for the system.

EGun5214: /* Problems and Discussions */

2022-04-30T16:34:40Z

Problems and Discussions

← Older revision		Revision as of 16:34, 30 April 2022
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	A Faraday Cup was initially planned to be included for current measurement, but due to logistical issues, we could not get the picoammeter (RBD 9103) that was indented for the project on time.		A Faraday Cup was initially planned to be included for current measurement, but due to logistical issues, we could not get the picoammeter (RBD 9103) that was indented for the project on time.

	Another reason for the low luminescence could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.		Another reason for the low luminescence could be due to a low vacuum. With all components installed, the pressure was relatively higher (<math>~10^{-4}</math> mbar) than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.

	===Filament alignment===		===Filament alignment===

EGun5214: /* Dim luminescence of phosphor */

2022-04-30T16:33:53Z

Dim luminescence of phosphor

← Older revision		Revision as of 16:33, 30 April 2022
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	As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly at the top layer. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected. To counter this, a thinner layer of phosphor could be fabricated.		As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly at the top layer. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected. To counter this, a thinner layer of phosphor could be fabricated.

	A Faraday ~~Cage~~ was planned ~~initially~~, but due to logistical issues, we could not get the ~~nanoammeter~~ (RBD 9103) that was indented for the project on time.		A Faraday Cup was initially planned to be included for current measurement, but due to logistical issues, we could not get the picoammeter (RBD 9103) that was indented for the project on time.

	Another reason could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.		Another reason for the low luminescence could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.

	===Filament alignment===		===Filament alignment===

EGun5214: /* Fully Assembled System */

2022-04-30T16:32:30Z

Fully Assembled System

← Older revision		Revision as of 16:32, 30 April 2022
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	[[File:Full setup.jpeg\|640px\|thumb\|none\|Fully assembled set-up]]		[[File:Full setup.jpeg\|640px\|thumb\|none\|Fully assembled set-up]]

	The system was fully assembled with the RP and TMP installed with a gauge reading ~~off~~ the chamber pressure. The PHYWE PSUs were also attached through the external feed-throughs.		The system was fully assembled with the RP and TMP installed with a gauge reading the chamber pressure. The PHYWE PSUs were also attached through the external feed-throughs.

	==Measurements and Tests==		==Measurements and Tests==

EGun5214: /* Dim luminescence of phosphor */

2022-04-30T16:30:53Z

Dim luminescence of phosphor

← Older revision		Revision as of 16:30, 30 April 2022
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	When the set-up was running, the glow of the phosphor was barely observed. This could be attributed to the thickness of the phosphorus and the spot size.		When the set-up was running, the glow of the phosphor was barely observed. This could be attributed to the thickness of the phosphorus and the spot size.

	As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected.		As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly at the top layer. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected. To counter this, a thinner layer of phosphor could be fabricated.

			A Faraday Cage was planned initially, but due to logistical issues, we could not get the nanoammeter (RBD 9103) that was indented for the project on time.

	Another reason could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.		Another reason could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.

EGun5214: /* Dim luminescence of phosphor */

2022-04-30T16:26:21Z

Dim luminescence of phosphor

← Older revision		Revision as of 16:26, 30 April 2022
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	As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected.		As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected.

	Another reason could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~~~10 \times~~ 10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.		Another reason could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.

	===Filament alignment===		===Filament alignment===

EGun5214: /* Experiment and Results */

2022-04-30T16:22:49Z

Experiment and Results

← Older revision		Revision as of 16:22, 30 April 2022
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	==Experiment and Results==		==Experiment and Results==

			The experiment was conducted after pumping down the chamber for several hours in a dark environment. Care was taken such that the 1000 V PSU was provided with ample safety precautions.

	The final parameters were tuned with similar simulation parameters.		The final parameters were tuned with similar simulation parameters.
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	\|}		\|}

	As mentioned, because of the identical potential for the Anode and Einzel lens, the same power supply was able to be used for both of them while a separate one was used for the Wehnelt cylinder.		As mentioned, because of the identical potential for the Anode and Einzel lens, the same power supply was able to be used for both of them while a separate one was used for the Wehnelt cylinder.

	[[File:HPS.jpeg\|360px\|thumb\|none\|Power supply to Wehnelt cylinder at -200 V and 1 kV to anode and Einzel lens]]		[[File:HPS.jpeg\|360px\|thumb\|none\|Power supply to Wehnelt cylinder at -200 V and 1 kV to anode and Einzel lens]]

EGun5214: /* Conclusion */

2022-04-30T16:18:41Z

Conclusion

← Older revision		Revision as of 16:18, 30 April 2022
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	==Conclusion==		==Conclusion==
	The electron beam was observed, but limitations meant that we could not measure the beam spot size. Further attempts and modifications will be planned such that the electron gun will be working, for the purpose of other projects that requires it.		The electron beam was observed, but limitations meant that we could not measure the beam spot size nor other parameters.

			Further attempts and modifications will be planned such that the electron gun will be working for the purpose of other projects that requires it, such as a compact electron imaging system.

EGun5214: /* Problems and Discussions */

2022-04-30T16:16:13Z

Problems and Discussions

← Older revision		Revision as of 16:16, 30 April 2022
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	Throughout the project, various obstacles were met. Methods to overcome them were attempted but not successful.		Throughout the project, various obstacles were met. Methods to overcome them were attempted but not successful.

	===Dim luminescence of ~~phosphorus~~===		===Dim luminescence of phosphor===
	When the set-up was running, the glow of the phosphor was barely observed. This could be attributed to the thickness of the phosphorus and the spot size.		When the set-up was running, the glow of the phosphor was barely observed. This could be attributed to the thickness of the phosphorus and the spot size.

	As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected.		As mentioned previously, the spot size of the beam would be a few hundred microns. With such a spot size and a thick phosphorus layer, when the beam hits the bottom of the layer, it would illuminate only slightly. The phosphor would thus only appear to slightly "glow" and not allowing us to see the spot as expected.

	Another reason could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10 \times 10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again. Unfortunately, it could not be done on time for the module.		Another reason could be due to a low vacuum. With all components installed, the pressure was relatively higher at <math>~10 \times 10^{-4}</math> mbar than what was characterised above. One way to overcome this is to clean all components thoroughly again (sandblasting, chemical cleaning, etc.). Unfortunately, it could not be done on time for the module.

	===Filament alignment===		===Filament alignment===
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	The project was originally planned to be located in the Physics Acoustic Room (S13 level 1). However, during the course of designing the chamber, the location was shifted to a lab within the Centre of Ion Beam Applications (CIBA), at S7 level 1 as the tools were more readily available there.		The project was originally planned to be located in the Physics Acoustic Room (S13 level 1). However, during the course of designing the chamber, the location was shifted to a lab within the Centre of Ion Beam Applications (CIBA), at S7 level 1 as the tools were more readily available there.

	The chamber design was revised intensively to before the current version was ~~completed~~. The original design had to be scrapped due to a lack of components.		The chamber design was revised intensively before the current version was reached. The original design had to be scrapped due to a lack of components.

	===Future===		===Future===

EGun5214: /* Experiment and Results */

2022-04-30T16:10:59Z

Experiment and Results

← Older revision		Revision as of 16:10, 30 April 2022
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	\|}		\|}

	As mentioned, because of the identical potential for the Anode and Einzel lens, the same power supply was able to be used for both of them while a separate one was used for the ~~Wenhelt Cylinder~~.		As mentioned, because of the identical potential for the Anode and Einzel lens, the same power supply was able to be used for both of them while a separate one was used for the Wehnelt cylinder.

	[[File:HPS.jpeg\|360px\|thumb\|none\|Power supply to Wehnelt cylinder at -~~200V~~ and ~~1kV~~ to anode and Einzel lens]]		[[File:HPS.jpeg\|360px\|thumb\|none\|Power supply to Wehnelt cylinder at -200 V and 1 kV to anode and Einzel lens]]

	The filament power supply was set to 10 V DC. Current provided was 0.1104 A as shown on the filament PSU (Keithley 2200 DC Power Supply).		The filament power supply was set to 10 V DC. Current provided was 0.1104 A as shown on the filament PSU (Keithley 2200 DC Power Supply).
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	[[File:Lumonous.jpeg\|360px\|thumb\|none\|Phosphor glow due to focused electron beam]]		[[File:Lumonous.jpeg\|360px\|thumb\|none\|Phosphor glow due to focused electron beam]]

			Due to the low intensity of the fluorescence, no useful data could be taken. The discussion is included in the section below.

	==Problems and Discussions==		==Problems and Discussions==