Michel wrote. > > > Measuring the time-of-flight of the electrons from flash to detection > > at the top/electrometer to determine/prove gravity repulsion might be a > > chore > > You're right Fred, what would be needed is not an electrometer maybe > (mechanical stuff with inertia isn't it?) > > What would you think of the following setup: > > - Grounded photo-cathode at the bottom of the tube > The S1 (Cs-CsO- on Ag) Photoemissive surface is the one with the photon peaks at ~ 330 and ~ 800 nanometers with a threshold of about 1254 nm (1.0 eV IR) Cr YAG Laser?
http://ssd-rd.web.cern.ch/ssd-rd/Pad_HPD/Principle/photocathodes.htm 0.1 eV electrons have a velocity v = (0.1* 2*1.6e-19/9.1e-31)^1/2 = 1.875e5 meters/sec! Electron space charge will act as a "velocity filter" that allows the higher energy electrons out, but if there is a repulsive gravity force F(gr) = m*g = = 9.1e-31*9.8 = 8.9e-30 newtons on an electron and the restraining electric field (E volts/meter) force F(e) = E*q = 1.6e-19 newtons at E = 1.0 volt/meter, there is a problem. :-) > > - Grounded grid at the top of the tube (so tube is fieldless) > Sounds like a Faraday cup approach, Michel. > > - Plate above the grid connected to positive terminal of a low voltage power > supply whose negative terminal is grounded. > > Time of flight would be time between laser flash and power supply current > pulse wouldn't it? > Yes. But the ~ 5 microseconds/meter 0.1 eV electrons get there ahead of the S - 0.5 * a* t^2 ~ = 3.0e-10 meters gravity repelled electrons traveled. OTOH. if you light pulse it and wait for the "slowpokes" ? Fred > Michel > > P.S. Nice applet indeed! > P.P.S. No I know nothing about vacuum tubes (was born in 57) > > > ----- Original Message ----- > From: "Frederick Sparber" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Friday, April 14, 2006 3:56 AM > Subject: Re: Electrogravity & Proton Repulsion of Electrons > > > > Michel Jullian writes. > >> > >> Ingenious! (Faraday cup and saucer, indeed ;) > >> > > Very British for tea, what? :-) > >> > >> For electrons slow enough not to produce secondary emission I would have > >> thought a simpler collecting device, not a hollow one, would work: a grid > >> surrounding a solid conductor, the latter positive wrt the former. > >> > > In vacuum tubes (if you are old enough to remember them) > > they call that the suppressor grid, usually tied > > internally to the cathode. > >> > >> For the ultra-low energy emitter photo-emission should work better than > >> thermo-emission as it will give more homogeneous energies (precisely > >> controlled by incident light wavelength aren't they?) > >> > > I think an LED/or laser could cause low energy-low velocity electron > > emission from a low work function photo-emissive material. > > > > One of Walter Fendt's applets for materials: > > > > http://www.walter-fendt.de/ph14e/photoeffect.htm > > > > Measuring the time-of-flight of the electrons from flash to detection > > at the top/electrometer to determine/prove gravity repulsion might be a > > chore > > > > Fred > >> > >> Michel > >> > > > > > >
