• S. Boucher, X.D. Ding, A.Y. Murokh
  RadiaBeam, Marina del Rey

Self-contained irradiators are used for a number of applications, such as blood irradiation to prevent Graft-Versus-Host-Disease, biomedical and radiation research, and detector calibration. They typically use a sealed Cs-137 source to irradiate an item within a treatment compartment. The US National Research Council has identified as a priority the replacement of such high-activity sources with alternative technologies, in order to prevent them from falling into the hands of terrorists for use in a Radiological Dispersal Device ("dirty bomb"). RadiaBeam Technologies is developing a novel, compact, low-cost linear accelerator "the MicroLinac" for use in self-contained irradiators in order to effectively replace Cs-137 in such devices. A previous version of the MicroLinac, originally developed at SLAC, was designed to produce 1 MeV electron energy and 10 μA of average current. RadiaBeam has redesigned the linac to produce 1.5 MeV and 20 μA current, in order to match the penetration and dose rate of a typical blood irradiator. This paper describes the new design of the MicroLinac and our future development plans.

• R.B. Agustsson, G. Andonian, A.Y. Murokh, R. Tikhoplav
  RadiaBeam, Santa Monica
• D.L. Griscom
  NRL, Washington D.C.

A beam profile monitor utilizing the technological advances in fiber optic manufacturing to obtain micron level resolution is under development at RadiaBeam Technologies. This fiber-optic profiling device would provide a lost cost, turn-key solution with nominal operational supervision and requires minimal beamline real estate. We are currently studying and attempting to mitigate the technical challenges faced by a fiber optic based diagnostic system with a focus on radiation damage to the fibers and its effect on signal integrity. Preliminary irradiation studies and conceptual operation of the system are presented.

• L. Faillace, R.B. Agustsson, P. Frigola, A.Y. Murokh
  RadiaBeam, Santa Monica
• D. Alesini
  INFN/LNF, Frascati (Roma)
• J.B. Rosenzweig
  UCLA, Los Angeles, California
• V. Yakimenko
  BNL, Upton, Long Island, New York

The quest for detailed information concerning ultra-fast beam configurations, phase spaces and high energy operation is a critical task in the world of linear colliders and X-ray FELs. Huge enhancements in diagnostic resolutions are represented by RF deflectors. In this scenario, Radiabeam Technologies has developed an X-band Travelling wave Deflector (XTD) in order to perform longitudinal characterization of the subpicosecond ultra-relativistic electron beams. The device is optimized to obtain a single digit femtosecond resolution using 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory; however, the design can be easily extended to be utilized for diagnostics of GeV-class beams. The XTD design fabrication and tuning results will be discussed, as well as installation and commissioning plans at ATF.

* J. England et al., "X-Band Dipole Mode Deflecting Cavity for the UCLA Neptune Beamline".
** D. Alesini, "RF deflector-based sub-ps beam diagnostics: application to FELs and advanced accelerators".

• A.Y. Murokh, M. Ruelas, R. Tikhoplav
  RadiaBeam, Santa Monica
• D.M. Gassner, E. Pozdeyev
  BNL, Upton, Long Island, New York

For high average current electron accelerators, such as Energy Recovery Linacs (ERL), the characterization of basic electron beam properties requires non-interceptive diagnostics. One promising non-destructive approach for a high average current beam diagnostic is the laser wire scanner (LWS). RadiaBeam Technologies is developing an inexpensive, stand-alone laser wire scanner system specifically adapted to ERL parameters. The proposed system utilizes distinctive features of ERL beams, such as a relatively long bunch length and ultra-high repetition rate, to maximize photon count while using off the shelf laser technology. The RadiaBeam LWS prototype presently under development will be installed and commissioned at the Brookhaven National Laboratory (BNL) ERL facility. This system's design and projected performance are discussed herein.

• G. Andonian, A.Y. Murokh, A.G. Ovodenko, M. Ruelas, R. Tikhoplav
  RadiaBeam, Marina del Rey
• D. Dooley
  Spectrum Detector, Lake Oswego, Oregon
• U. Happek
  UGA, Athens, Georgia
• S. Reiche
  PSI, Villigen

This paper reports on the progress of the development of a bunch length diagnostic for high brightness beams. The diagnostic, termed the real time interferometer, is a single shot, autocorrelator that outputs the interferogram of coherent radiation emitted from compressed, high-brightness beams. The device uses all-reflective terahertz optics as well as a highly sensitive pyroelectric-based detector array. For initial testing, coherent transition radiation is used, however, the diagnostic can be used in a non-destructive manner if coherent edge or synchrotron radiation is employed. Current research includes diagnostic design and preliminary tests conducted at the BNL Accelerator Test Facility.

• R. Tikhoplav, A.Y. Murokh
  RadiaBeam, Santa Monica
• I. Jovanovic
  Purdue University, West Lafayette, Indiana

Of particular interest to X-ray FEL light source facilities is Enhanced Self-Amplified Spontaneous Emission (ESASE) technique. Such a technique requires an ultrafast (20-50 fs) high peak power, high repetition rate reliable laser systems working in the mid-IR range of spectrum (2μm or more). The approach of this proposed work is to design a novel Ultrafast Mid-IR Laser System based on optical parametric chirped-pulse amplification (OPCPA). OPCPA is a technique ideally suited for production of ultrashort laser pulses at the center wavelength of 2 μm. Some of the key features of OPCPA are the wavelength agility, broad spectral bandwidth and negligible thermal load.

• L. Faillace, R.B. Agustsson, P. Frigola, A.Y. Murokh
  RadiaBeam, Marina del Rey
• V.A. Dolgashev
  SLAC, Menlo Park, California
• J.B. Rosenzweig
  UCLA, Los Angeles, California

There is growing demand from the industrial and research communities for high gradient, compact RF accelerating structures. The commonly used S-band SLAC-type structure has an operating gradient of only about 20 MV/m; while much higher operating gradients (up to 70 MV/m) have been recently achieved in X-band, as a consequence of the substantial efforts by the Next Linear Collider (NLC) collaboration to push the performance envelope of RF structures towards higher accelerating gradients. Currently however, high power X-band RF sources are not readily available for industrial applications. Therefore, RadiaBeam Technologies is developing a short, standing wave S-band structure which uses frequency scaled NLC design concepts to achieve up to a 50 MV/m operating gradient at 2856 MHz. The design and prototype commissioning plans are presented.