Fermilab T-1007: Optical Cavity Test Bench in the MP8 beamline Aaron S. Chou Wilson Fellow, FNAL All Experimenters Meeting January 10, 2011 Enables tests of long-baseline optical beams Axions Holographic Information bound

asdf A.S.Chou, All Experimenters Meeting, 1/10/ eV: Neutrino oscillations. dark energy via SDSS, DES, laser search, etc 10 3 GeV: Tevatron, LHC, dark matter direct detection 10 5 GeV: cosmic ray showers GeV: axion-photon oscillations GeV: holographic noise Laser experiments to probe the highest energy scales 1 eV-1 GeV: Chemistry, nuclear physics, strong interactions eV: Hubble scale Every photon in a laser beam is in the same state, so coherence effects can amplify ultraweak phenomena

The new MP8 laser lab is now the largest laser lab on-site. (~50m long x 7.5’ wide) Currently installing a vacuum-enclosed 40m optical beamline. Thanks to AD Tevatron vacuum group! (McCormick, Dymond, Lambert, Williams, et.al.)

Laser shutter interlock system + kill switch for safe operation of class 4 lasers. (Thanks AD interlock group, ES&H laser safety group) A.S.Chou, All Experimenters Meeting, 1/10/11 4

End station vacuum vessels hold custom optical cavity mirrors and eventually beamsplitters A.S.Chou, All Experimenters Meeting, 1/10/11 5

Portable clean rooms (class <100?) mounted on ceiling rails Allows dust-free access to vacuum enclosed optics. Requirements on optics cleanliness: Axions: <5 ppm scattering loss Holometer: <50 ppm scattering loss Thanks to PPD mechanical group: Korienek, Lindenmeyer, Nebel, Taccki 6 A.S.Chou, All Experimenters Meeting, 1/10/11

Current optical device R&D in Linac Laser Lab. The MP8 lab will relieve some of this congestion! Tests of full-scale 40m optical cavities planned for early A.S.Chou, All Experimenters Meeting, 1/10/11 7 Frequency reference cavity Mode-cleaning cavity 2 kHz PZT- actuated 2” mirror mount Laser auto-correlation test 25 MHz RF control system

Application 1: Search for couplings to photons of new axion-like particles by photon-photon scattering A.S.Chou, All Experimenters Meeting, 1/10/11 8 Use optical cavities to improve world-leading GammeV coupling sensitivity by 4 orders of magnitude. (Increase event rate by )

Application 2: The Fermilab Holometer: Interferometer probe of the quantum structure of space-time at the Planck scale GeV Fermilab:  A. S. Chou (co-PI, acting project manager), H. Glass, C. Hogan, E. Ramberg, J. Steffen, C. Stoughton, R. Tomlin, J. Volk, W. Wester. MIT LIGO:  S. Waldman, R. Weiss U.Chicago  S. Meyer (co-PI) U. Michigan LIGO  D. Gustafson Caltech LIGO  S.Whitcomb A.S.Chou, All Experimenters Meeting, 1/10/11 9 Large overlap in both scientific staff and R&D topics with the FNAL axion group. The large cavity-recycled photon flux (up to photons/s) can be used either for searches for rare events or to make precise position measurements. Tentative Schedule: (?): Holometer 2013-? : Axions

The Holographic Principle implies a maximum information density in the universe A.S.Chou, All Experimenters Meeting, 1/10/11 10 R. Bousso Black hole entropy S = M pl 2 Area / 4 Our apparently 3D world is actually 2D and has a bandwidth limit ?!?!

A.S.Chou, All Experimenters Meeting, 1/10/11 11 How can we tell if we are living in the

A.S.Chou, All Experimenters Meeting, 1/10/11 12 Look closely at beamsplitter position to detect the fuzziness of space-time. Detect via the resulting phase noise in the interference fringe. (Hogan)

The proposed 40m Fermilab Holometer will search for correlations in the noise between 2 neighboring interferometers A.S.Chou, All Experimenters Meeting, 1/10/11 13 Cross-correlate the photocurrents from the two devices. Need only a few hours integration time for correlated noise to beat random uncorrelated noise. Diagnostic knob: The holographic correlation signal can be turned off by spatially separating the two devices so the beamsplitters cannot be causally connected.

Concrete vacuum pipe support bases installed outside MP8 in preparation for a 40m interferometer test in Summer, 2011.

100 MHz data acquisition and RF cavity/interferometer control electronics  Funded by U.Chicago SCI grant (Meyer, Chou, Stoughton)  Digital feedback control to piezo actuators on the laser and mirror mounts  Currently being tested at FNAL MP8 laser lab A.S.Chou, All Experimenters Meeting, 1/10/11 16 Expected holographic cross- correlation signal between two photodiodes plotted vs delay time between the two data streams. Actual cross-correlation data taken with the digital DAQ. Delay time (us) Correlated power fraction