Task E - A0 and related activities A.C.MELISSINOS Faculty S.VORONOV Res. Assoc. (2003) R.TIKHOPLAV Graduate Students S.SELETSKIY W.BUTLER --- NLC SOURCE DEVELOPMENT --- LASER ACCELERATION EXPERIMENT ELECTRON COOLING OF ANTIPROTONS IN RECYCLER A0 PHOTOINJECTOR (FERMILAB) SEARCH FOR COHERENT BACKGROUND FIELDS (proposed) PHENOMENOLOGY 11/14/2018 Task E/DOE review/ACM

A0 (FNPL) PHOTOINJECTOR --- Train of 800 pulses spaced 1 µs --- Charge per pulse > 1 nC --- Emittance ~ -mm-mr --- Pulse length < 1 ps Can be operated remotely from LBL, DESY EXPERIMENTS: --- Generation of flat beams --- Beam diagnostics for ultra-short pulses --- Plasma wakefield acceleration                                             Rochester built and operates/maintains/improves the injection laser 11/14/2018 Task E/DOE review/ACM

TEM01* (DOUGHNUT-SHAPE) MODE Nd:glass laser with wavelength =1054 nm is used; compressed and amplified it will deliver 1J in 1ps pulse The laser operates in the TEM01 mode Radial polarization (TEM01* mode) is used for symmetry reasons and to gain a factor of 2 in accelerating field 11/14/2018 Task E/DOE review/ACM

15 MeV 50 MeV 150 MeV 11/14/2018 Task E/DOE review/ACM

ELECTRON COOLING Electron Energy 3.5 MeV Electron Current 500 mA Cooling section length 20 m Preserve electron beam focussing by using longitudinal magnetic field 100 Gauss Tolerance on transverse field .001 Gauss Tolerance on beam loss < 2% 11/14/2018 Task E/DOE review/ACM

11/14/2018 Task E/DOE review/ACM

The angular spread of the beam must be less than 10-4 radians Uncompensated field Compensated field The angular spread of the beam must be less than 10-4 radians 11/14/2018 Task E/DOE review/ACM

DETECTION OF COHERENT FIELDS  Possibilities: Coherent axion field Dilaton field Quintessence field   +   -    In the LIGO interferometer  = 2(3x1014) is resonant; if  ±  is also resonant, The SIDEBANDS build up EXAMPLE: Coherent axion field h = 10-20 LIGO sensitivity h = 10-23 11/14/2018 Task E/DOE review/ACM

Response of the LIGO interferometer to a coherent high frequency wave incident at an angle of 30° The first peak is at 37.52 kHz 11/14/2018 Task E/DOE review/ACM

11/14/2018 Task E/DOE review/ACM

NEUTRINO SCATTERING IN A MAGNETIC FIELD Yaroslav University (2003) K.S.McFarland, A.C.Melissinos, N.V.Mikheev and W.W.Repko Yaroslav University (2003) ν + B → ν + γ (high energy) Conversion probability for 50 GeV neutrinos When B = 2.2 T L = 10 m 11/14/2018 Task E/DOE review/ACM

“RUNNING” OF THE GRAVITATIONAL COUPLING CONSTANT Solid line Classical Evolution Dotted line Unification with the Gauge couplings 11/14/2018 Task E/DOE review/ACM

Supplementary slides 11/14/2018 Task E/DOE review/ACM

11/14/2018 Task E/DOE review/ACM

11/14/2018 Task E/DOE review/ACM

Beam recirculation experiment with U-bend beam line Multiple improvements let us to demonstrate stable recirculation of 0.5 A electron beam Better understanding of beam optics and improvements in the gun and collector design made it possible to recirculate a beam of up to 1.7 A at 3.5 MV for several minutes – it’s 6 MW of beam power! Beam recovery after an interruption of a 1-A beam recirculation The use of a protection system, allowing to shut the gun off during interruptions, helped to avoid large drops of the Pelletron voltage and large pressure jumps. As a result, the beam recovery time is as low as 15 seconds 11/14/2018 Task E/DOE review/ACM

Cooling section Parameter Value Units Number of solenoids 10 Length of solenoids 190 cm Working magnetic field 100-150 G Maximal magnetic field 200 Solenoid current 4 A Coefficient of the shielding of solenoids 1000 Gap length 8 Number of gap correctors 20 Number of transverse field correctors per solenoid Requirements on the magnetic field in the cooling section Beam angular spread in the cooling section should be less than 10-4 rad. This requirement impose certain restrictions on the quality of the magnetic field in the cooling section. longitudinal field transverse field To cancel the solenoid edge effect electron at the entrance of the cooling section should have a proper angular momentum. To impart an angular momentum onto the electron beam the electron gun is immersed in a solenoidal magnetic field. Thus, a beam is produced by a 5-mm diameter cathode in a 600-G magnetic field and then propagated to the cooling section, where it is injected into a 150-G solenoid. Algorithm of field correction was used to set the field of required properties Simulation of electron’s motion in uncompensated magnetic field Simulation of electron’s motion in the compensated magnetic field 11/14/2018 Task E/DOE review/ACM

11/14/2018 Task E/DOE review/ACM

11/14/2018 Task E/DOE review/ACM