1. UCNA specs – JWM 9/4/7 Proton beam energy = 800 MeV Peak proton current = 40 uA Duty cycle = 1/10 (1 sec on, 10 sec off) Therefore time-averaged current is 4 uA. Source is designed to take 10 uA time-averaged. Spallation target is tungsten, 2cm diameter, 10 cm long. Cooling of spallation target achieved by flowing compressed He gas. The length of the red “beta spectrometer” at bottom center of next slide is about 5.5 m long Shielding is 9’ of steel and 6’ of concrete. People can walk around area when beam is on (provided shielding is all in place) Remote extraction handled by removing one shield block, then pulling out a package from custom-made block. (see picture) Thanks to M. Makela and A. Saunders from LANL for providing the numbers

2. Layout in Area B 800 MeV protons UCN Source beta- spectrometer polarizer magnet

3. proton beam direction shield package UCN port remote extraction

4. UCN to expt “prepolarizer” magnet polarizer magnet beta-spectrometer magnet UCN guide insertion future UCN guide path Status