Assessment of Physics, Applications and Construction Issues for the Proposed Magurele Short-Pulse Facility Silviu Olariu National Institute of Physics and Nuclear Engineering, Magurele, Romania

 MeV collider

 scattering

maximum of  cross section at ~ 0.76 MeV range of interest ~ MeV

Luminosity If two photon bunches moving in opposite directions and each containing N photons intersect over an area A, the number of scattering processes for a cross section  is

Generation of MeV photons using inverse Compton scattering on 120 MeV electron pulses generated by petawatt lasers The number of 120 MeV electrons generated by a laser pulse of 150 J and assuming a conversion efficiency of 10 % is 7.8 x 10^11 electrons. Using a laser pulse of 532 nm, these electrons generate, for a conversion efficiency of 80 %, N= 6.2 x 10^11 photons having an energy of MeV.

 scattering of MeV photons generated by two petawatt lasers Using two colinear petawatt lasers focused over an area A = 10^-6 cm^2 and for a  cross section of 10^-30 cm^2, the number of interactions is 0.39 per pulse. For a repetition rate of 1/min, this yields 23  interactions per hour.

 scattering with the 10 petawatt / 1 petawatt Vulcan lasers For the Vulcan laser, where there is a 10 petawatt beam and a 1 petawatt beam, and the repetition rate is 1 per 15 minutes, the  rate would be about two orders of magnitude lower.

Separation of the electron beams Divergence of electron beams: ~ 4 mrad Distance between the two planes were the electron beams are generated by the petawatt beams: ~ mc/qB For B = 10 T the distance between the planes is ~ 0.2 mm 10  m / 4 mrad = 2.5 mm

 scattering using two pulsed electron beams at 120 MeV A pulse of 250 pC contains 1.6 x 10^9 electrons. For an area A = 10^-6 cm^2 and for a  cross section of 10^-30 cm^2, the number of interactions is 2.5 x 10^-6. For a repetition rate of 10^2 per second, this yields 0.9 interactions per hour.

Comparison of  scattering using two petawatt lasers and two pulsed electron accelerators The  scattering rates become comparable for photon energies around 2.5 MeV. It is an open question if the rate of 1 per minute is realistic for the petawatt lasers, and it is an open question if the area A = 10^-6 cm^2 is realistic for the electron beams.

Comparison with Magurele Tandem accelerators 1  A of protons means 6 x 10^12 protons / s ,n reactions similar to p,d reactions

The Scientific case overestimates the yields Predictions concerning the N=126 experiment Fusion products, normal stopping 2 July 2010: 10^4 7 July 2010: 5 x 10^2 7 September 2010: 1.5 Scientific case: unchanged. 1.5 is still overestimated.

Neutron source Generation of thermal neutrons is weak

1.7 mil euro per year for heating, ventillation and air conditioning

Interesting options Positron tomography Magnetic resonance imaging Proton therapy center