Overview of Chemical Science and Engineering Divisions Low

Overview of Chemical Science and Engineering Division’s Low Energy Accelerator Facility (LEAF) Sergey Chemerisov, Argonne National Laboratory Chemical Science and Engineering Division October 7, 2010

LEAF facility at Argonne LEAF facility

Setting of the LEAF Building 211 Low energy Accelerator Facility Service Floor 20 Me. V electron linac 3 Me. V Van de Graaff A-004 Unexcavated E-001 E-024 A-011 A-035 Unexcavated D-032 Spec Room A-051 Unexcavated E-031 C-001 E-040 Cyclotron Vault D-001 LINAC Pit Unexcavated E-049 Instrument Room D-070 E-046 D-072 Cell 2 Chemistry Division 3 MEV Van De Graaff E-036 Scale 1 inch = 10 feet B-012 D-017 Unexcavated E-034 A-056 B-001 D-024 Unexcavated D-035 LINAC Cell A-053 Unexcavated Instrument Room E-010 Unexcavated Unexcavated

3 Me. V Van de Graaff accelerator

3 Me. V Van de Graaff accelerator facility Electron beam q e- energy 1 -3 Me. V q Pulse width 5, 12, 25, 55, 100 ns, 1 s - 1 ms or DC q Pulse rise time in nano second mode ~ 3 ns q Maximum electron current 500 A (administratively limited to 100 A) q Pulsed current 2 A (up to 5 A with reduced cathode lifetime) q Beam size 5 mm can be focused down to 1 mm spot q Energy stability ~1% Positive ion beam H+ or D+ q energy 1 -3 Me. V q Maximum current 500 A q DC only

3 Me. V Van de Graaff accelerator E-036 E-034 Chemistry Division 3 MEV Van De Graaff E-040 E-049 Instrument Room E-046

VDG accelerator Pit east port

VDG accelerator Pit west port

20 Me. V Linac

General description n n n n L – band, 1. 3 GHz Energy 2 -22 Me. V 2 accelerating structures (11 cavities, 11. 83 Me. V per structure unloaded) 2 klystrons (20 MW peak, 50 KW average) 0. 0025 klystron duty factor Pulse width 30 ps - 5 s 2. 5 A peak current in steady state mode 1000 A peak current in 30 ps pulse

Beam Characteristics n Steady state mode Pulse width 0. 5 - 5 s (train of 30 ps pulses separated by 770 ps) Repetition rate 60 Hz (100 Hz power supply limited) Peak current up to 2. 5 A at 14 Me. V Beam size ~1 cm n Average current: 2. 5 A x 0. 0025 (klystron duty factor)=6. 25 m. A PFN line is limited to 300 Hz and 5 s n Pico second (single pulse) mode: 30 ps single pulse High peak intensity achieved by compressing 4 ns pulse with 1/12 sub harmonic buncher n Nano second mode: 4, 6, 8, 10, 20, 40, 80, 100 ns pulses

20 Me. V Linac Instrument Room D-032 Spec Room D-024 D-035 LINAC D-017 D-001 LINAC Pit Cell D-070 D-076 D-072 Cell 2

Linac accelerator Cell 1

Plans for linac upgrade Driver: Medical isotope production. Step 1. Already implemented Power upgrade: increase repetition rate to 270 Hz to achieve 40 k. W total power in the beam Step 2. Completion planned for June 2011 Beam energy upgrade: Increase beam energy to 58 Me. V an keeping all other machine parameters same

Present condition of positron production line at Chemistry division linac Front end bends to separate electrons from positrons shielding Output end detector