Part XIII.

6. Bob H. Smith et al., The Electrical Aspects of the UCRL 740-Mev Synchrocyclotron, UCRL-3779 Rev., October 2, 1957.

7. Robert L. Thornton, Frequency-Modulation and Radiofrequency System for the Modified Berkeley Cyclotron, UCRL-3362, April 3, 1956.

8. Robert R. Wilson, Particle Accelerators, Scientific American 198, 64-76 (March 1958).

APPENDIX

SUMMARY OF SPECIFICATIONS

Present fields of research % of time -------------------------- --------- Nuclear physics 86 Nuclear chemistry 2 Biophysics 12

Scheduled operation 156 hours/week

Performance

Internal Beams

Alpha Helium-3 Protons Deuterons particles ions ------- --------- --------- -------- Maximum energy (Mev) 730 460 910 1140 Energy spread (Mev) 55 Beam intensity Average current (a) 0.75 0.75 0.25 Peak current (a) 120 120 40 Beam radius, maximum (in.) 82 82 82 82 Time required for acceleration (msec) 6 4.5 4.5 Number of revolutions during acceleration 75,000 60,000 60,000 Distance traveled during acceleration (miles) 450 360 360 Velocity at maximum energy (% of speed of light) 82 60 60 69 Mass increase at maximum energy (% of rest mass) 75 25 25 40 Range of full-energy particles (in. of aluminum) 37 12 7

External Beams

Physics cave Meson cave ----------------------- ------------------- Protons Neutrons ^+ ^+ ^- ------- -------- ------ -------- --------- Energy (Mev) 730 310 100|250 100| 300 Energy spread (Mev) 14 10| 20 10| 30 Beam area (cm^2) 25 40 100|100 100| 100 Flux (particles/cm^2-sec) 2x10^10 5x10^5 5x10^4 1000|100 1500|1000

Acceleration chamber (vacuum tank)

Size length (ft) 25 width (ft) 20 height (ft) 4

Material: mild steel

Operating pressure (mm Hg) 10^-5

Vacuum pumps: six 20-in. oil-diffusion pumps with 8-in. boosters: one Beach-Russ 750-cfm; one Kinney 300-cfm; two Kinney 105-cfm.

Pumping speed of oil-diffusion pumps (liters/sec) 20,000

Magnet

Core diameter (in.) 184 Pole-tip diameter (in.) 188.75 Pole gap at center (in.) 14 Magnetic field strength (gauss) at center 23,400 at radius of 82.2 in., where n = 0.2 22,275 Weight of steel (tons) 4,000 Magnet coils Main coils Auxiliary coils ---------- --------------- material solid copper hollow copper (1/4 x 4 in.) (1-3/16 x 1-1/16 in.) weight of copper (tons) 300 40 number of turns (total) 2,600 425 ampere turns 1.9 x 10^6 1.1 x 10^6 current (amp) 1600 2800 voltage (v) 550 560 power (kw) 900 1600 coolant oil water

Radiofrequency system

Dee system number of dees 1 size length (in.) 126 width (in.) 180 height (in.) 48 material: 1/64-in.-thick copper, stretched over a stainless steel frame dee aperture (in.) 4-3/16

Oscillator type: self-excited grounded-grid 10 tube: one Machlett ML5681 dc input, operating condition (kw) 10 dee bias, maximum dc (v) 2000

Protons Deuterons Alpha particles ------- --------- --------------- rf duty cycle (%) 38 28 28 dee-to-ground voltage, peak (kv) 9 6 6

Frequency-modulation system type: vibrating-reed (tuning-fork) capacitor number of units: two (two blades each) blades size width (in.) 45 length (in.) 32 thickness: tapered from 1.4 to 0.06 in. weight (lb) 500 vibrational frequency (cps) 64 electrical capacitance (f) 300 to 6,500 peak-to-peak excursion (in.) 1 minimum separation of blade and stator (mils) 50

Protons Deuterons Alpha particles ------- --------- --------------- frequency sweep (Mc) 36-18 18-13.5 18-13.5

Ion source: conventional open-arc type

Beam extractor

LeCouteur-type regenerator combined with magnetic channel

Building and facilities

Room dimensions diameter (ft) 160 height (ft) 90

Crane type: radial capacity (tons) 30 overhead span (ft) 77

Concrete shielding: 15 ft thick on sides, 4 ft on top

History

Design started: January 1940. Construction started: August 1940. First operation for deuterons and alpha particles: November 1946. for protons: December 1948. Rebuilt: 1955-1957.