| Title Page |
2 |
| Foreword |
4 |
| Acknowledgements |
6 |
| Contents |
8 |
| Chapter 1: Introduction |
12 |
| 1.1 Mass Driver History |
12 |
| 1.2 Mass Driver Applications |
16 |
| 1.3 Mass Driver Two |
18 |
| Chapter 2: Accelerator |
24 |
| 2.1 Drive Circuit |
24 |
| 2.2 SCR and Optical Trigger Circuits |
33 |
| Chapter 3: Ohmic Bucket |
38 |
| 3.1 Ohmic Bucket Requirements |
38 |
| 3.2 Ohmic Bucket Circuit Analysis |
42 |
| 3.3 Ohmic Bucket Design |
47 |
| 3.4 Ohmic Bucket Capacitor Bank and Controller |
50 |
| Chapter 4: Recharging System |
58 |
| 4.1 Recharging Requirements |
58 |
| 4.2 Recharging Circuit Analysis |
65 |
| 4.3 Recharging Capacitor Bank |
71 |
| 4.4 Recharging Controller and SCR Trigger Circuitry |
80 |
| 4.5 Recharge System Performance |
91 |
| Chapter 5: Instrumentation And Control |
96 |
| 5.1 Capacitor Bank Voltage Monitoring |
96 |
| 5.2 Capacitor Bank Current Monitoring |
100 |
| 5.3 SCR Trigger Pulse Recording |
100 |
| Chapter 6: Accelerator Test Firing Results |
102 |
| 6.1 Theoretical Performance |
102 |
| 6.2 Test Firing Results |
116 |
| Chapter 7: Summary |
132 |
| 7.1 Mass Driver System Performance |
132 |
| 7.2 Mass Driver Two Results |
141 |
| 7.3 Suggestions for Future Work |
143 |
| References |
146 |
| Figures |
20 |
| 1.1 Mass Driver Two Assembly |
20 |
| 1.2 Mass Driver Two during early testing with ohmic bucket. |
21 |
| 1.3 Control circuitry during early testing with ohmic bucket |
21 |
| 1.4 Mass Driver Two instrumentation and control circuitry. |
22 |
| Mass Driver Two accelerator |
23 |
| 2.1 Six drive coils of phase 1, |
24 |
| 2.2 Drive coil winding |
25 |
| 2.3 Attachment of flexible lead to drive coil |
25 |
| 2.4 Attachment of neutral bus for phase one of sector four. |
26 |
| 2.5 Construction of top drive coil clamp. |
27 |
| 2.6 Construction of SCR feeder strips |
31 |
| 2.7 Assembly of SCR feeder strips |
32 |
| 2.8 Preliminary testing of SCR and optical trigger circuits |
33 |
| 2.9 Test firing of drive circuit with prototype optical and SCR trigger circuit boards |
34 |
| 2.10 Alignment and testing of optical and SCR trigger circuit boards in phase two |
35 |
| 3.1 Modular ohmic bucket |
39 |
| 3.2 Ohmic bucket capacitor bank |
39 |
| 3.3 Ohmic bucket chilldown with liquid nitrogen |
40 |
| 3.4 Ohmic bucket caught by backstop after a test firing |
41 |
| 3.5 Basic ohmic bucket circuit |
42 |
| 3.6 Ohmic bucket circuit |
43 |
| 3.7 Ohmic bucket current waveform. |
45 |
| 3.8 Auxiliary SCR trigger circuit |
52 |
| 3.9 Ohmic bucket controller logic. |
53 |
| 3.10 2 KV ohmic bucket capacitor bank |
54 |
| 3.11 2 KV ohmic bucket circuit |
55 |
| 3.12 2 KV ohmic bucket capacitor bank charging circuit |
56 |
| 4.1 Simplified recharge circuit. |
65 |
| 4.2 Recharging system test circuit |
66 |
| 4.3 Simplified recharge circuit |
67 |
| Fig. 4.4 Recharge capacitor bank for phanse one and two of the accelerator |
71 |
| 4.5 Interior of recharge capacitor bank showing shelves of capacitors and SCR trigger circuit. |
72 |
| 4.6 Recharging capacitor bank circuit |
73 |
| 4.7 Polarity reversing switch for recharging system |
74 |
| 4.8 Interconnecting feeder for recharge capacitor bank |
75 |
| 4.9 Side view of accelerator showing feeder strips connecting recharge capacitor bank to sector capacitor |
76 |
| 4.10 Phase one sector capacitor |
77 |
| 4.11 Recharging capacitor bank charging circuit |
79 |
| 4.12 Recharging system event sequence |
81 |
| 4.13 Recharging controller block diagram |
82 |
| 4.14 Switching circuit |
83 |
| 4.15 Current clipping circuit |
84 |
| 4.16 Capacitor voltage amplifier circuit |
85 |
| 4.17 Scope trigger circuit |
86 |
| 4.18 Construction of recharging controller |
87 |
| 4.19 SCR trigger circuit block diagram for recharging system |
89 |
| 4.20 SCR trigger circuit for recharging system |
90 |
| 4.21 Sector capacitor voltage and recharge current waveforms |
93 |
| 5.1 Balanced voltage Divider circuit |
96 |
| 5.2 Fan in circuit output. |
101 |
| 6.1 Current and voltage waveforms during the passage of one bucket coil |
102 |
| 6.2 Basic drive coil configuration for Mass Driver Two |
103 |
| Ohmic bucket acceleration versus sector capacitor initial voltage at different α |
104 |
| 6.4 Ohmic bucket (α = 0.63) velocity vs. firing number at different bucket coil currents with sector capacitor voltage at 300V |
111 |
| 6.5 Ohmic bucket (α = 0.63) velocity vs. firing number at different sector capacitor voltages with bucket coil current = 33,600 amp turns. |
112 |
| 6.6 Drive current waveform for test no. 1 showing a recharge failure |
121 |
| 6.7 Drive current waveform for test no. 2 showing a recharge failure |
121 |
| 6.9 Drive current waveform for test no. 4. |
122 |
| 6.10 Drive current waveforms for test no. 5. |
123 |
| 6.11 Drive current waveforms for test no. 6. |
123 |
| 6.12 Drive current waveforms test no. 7. |
124 |
| 6.13 Drive current waveforms for test no. 8. |
124 |
| 6.14 Drive current waveforms for test no. 9. |
125 |
| 6.15 Drive current waveforms for test no. 10 |
125 |
| 6.16 Drive current waveforms for test no. 11. |
126 |
| 6.17 Drive current waveforms for test no. 12. |
127 |
| 6.18 Drive current waveforms for test no. 13 |
128 |
| Fig. 6.19 Drive current waveforms for test no. 14 |
129 |
| 7.1 Mass Driver Reaction Engine block diagram |
133 |
| 7.2 Closed loop mass driver system efficiency |
134 |
| 7.3 Disc Pack phase control SCR specific mass |
137 |
| Tables |
29 |
| 2.1 Phase One Circuit Parameters |
29 |
| 2.2 Phase Two Ringing Periods |
30 |
| 2.3 Firing Delays in Optical Trigger Circuit Boards |
36 |
| 3.1 Total Ohmic Bucket Current for α = 0.514 Bucket |
46 |
| 3.2 Ohmic Bucket Parameters |
47 |
| 3.3 Ohmic bucket resistance as a function of time after removal from liquid nitrogen |
48 |
| 3.4 Ohmic bucket resistance before and after firing at different voltages |
49 |
| 3.5 Ohmic bucket resistance before and after firing at different voltages |
49 |
| 4.1 Phase One Accelerator Drive Coil Efficiency with no Energy Transfer to Bucket |
60 |
| 4.2 Phase One Accelerator Recharge Requirements for Low and High Demand |
63 |
| 4.3 Recharge system test circuit parameters |
92 |
| 4.4 Recharge system test circuit results |
92 |
| 4.5 Recharge system circuit voltages |
94 |
| 4.7 Recharge system circuit parameters |
95 |
| 5.1 Voltage Divider Card Calibration |
98 |
| 5.2 Voltage Divider Card Calibration |
99 |
| 6.1 Ohmic bucket acceleration with: mass = 500gms, in j. vel. = 15 m/sec, α= 0.73, initial voltage = 750 V, and bucket current = 15,000 amp turns |
106 |
| 6.2 Ohmic bucket acceleration with: mass = 500gms, inj. vel. = 15 m/sec, α = 0.73, initial voltage = 750 V, and bucket current = 20,000 amp turns |
107 |
| 6.3 Ohmic bucket acceleration with: mass = 488gms, inj. vel. = 10 m/sec, α = 0.63, initial voltage = 300V, and bucket current = 13,000 amp turns |
109 |
| 6.4 Ohmic bucket acceleration with: mass = 488gms, inj . vel. = 10 m/sec, α = 0.63, initial voltage = 750V, and bucket current = 33,600 amp turns |
110 |
| 6.5 Superconducting bucket acceleration with: mass = 1 Kg, inj. vel. = 15 m/sec, α = 0.514, initial voltage = 750V, and bucket coil current = 42,750 amp turns |
113 |
| 6.6 Superconducting bucket acceleration with: mass = 1 Kg, inj. vel. = 15 m/sec, α = 0.514, initial voltage = 750V, and bucket coil current = 80,000 amp turns |
114 |
| 6.7 Ohmic bucket deceleration with: mass = 500gms, input vel. = 112 m/sec, α = 0.514, initial voltage = 750V, and bucket current = 45,000 amp turns |
115 |
| 6.8 Ohmic bucket and injector parameters. |
118 |
| 6.9 Phase one parameters |
119 |
| 6.10 Phase two parameters |
120 |
| 6.11 Summary of Velocities |
130 |