Daresbury Laboratory, Warrington, WA4 4AD, UK

1
The Free Radical Research Facility at Daresbury
Laboratory (FRRF_at_Daresbury)
R Edge1,2, DJ Holder3 and S Navaratnam1,4 1.
FRRF_at_Daresbury. 2. North East Wales Institute. 3.
ASTeC, Daresbury Laboratory. 4. University of
Salford.
Introduction

• Laser flash photolysis - NdYAG laser - 15ns
  266nm, 355nm and 532nm pulses, up to 500mJ.
• Time-resolved resonance Raman spectroscopy (TR3)
  - pulsed laser system synchronised with either
  linac pulses or NdYAG laser pulses.
• Confocal microscopy - Pulsed titanium sapphire
  laser - maximum scan speed of 1 frame/second.
• Time-resolved detection systems - optical
  absorption and emission, conductivity, resonance
  Raman at variable temperatures (77K - 350K).
• Single wavelength and multiple wavelength
  detection systems.
• Facility available for up to two 11 hour
  sessions per day.
• Fully staffed for complete service.
• Fully equipped support laboratories.
• EU funding provides access to users from the
  European
• Union and Associated states (see website).

This is a new facility at Daresbury Laboratory,
comprising of the complementary techniques of
pulse radiolysis, laser flash photolysis, ESR,
Confocal microscopy, time-resolved resonance
Raman spectroscopy, time-resolved luminescence
spectroscopy to study free radicals and excited
states of biologically important molecules.
Free radicals

• In biology, free radicals are frequently
  implicated in disease
• In motor neurone disease, for example, a mutant
  form of the enzyme superoxide dismutase, which
  normally protects against free radical damage,
  becomes a potent source of damaging hydroxyl
  radicals.
• In heart disease (atherosclerosis), free
  radicals lead to the oxidation of fats in the
  blood and hence to the formation of
  artery-blocking plaques.
• Protection is available from natural
  antioxidants, such as vitamins E and C,
  flavonoids and carotenoids, which intercept
  damaging free radicals.
• In chemistry, the damaging effects of free
  radicals are experienced by the nuclear industry.
  Ionising radiation produces free radicals which
• Degrade polymers,
• Decompose solvents (including aqueous systems)
• Not all free radicals are bad news however, as
  some may also be beneficial
• Radiotherapy induces free radicals which destroy
  cancerous cells.
• Blood pressure is regulated by the action of
  nitric oxide, a relatively long-lived free
  radical.
• Photosynthesis involves free radicals.
• Some drugs exert their effects by free-radical
  mechanisms.

The Facility

• Pulse radiolysis - 12 MeV electron linac
  provides single or multiple (up to 10 Hz) pulses
  of electrons.
• Fully-calibrated digital control of pulse length
  in the range 220ns to 2.2µs - doses up to 20
  Grays per shot.

Current Research Areas

• Bioactivation,
• Pigmentation,
• Cuticle sclerotization,
• Organic synthesis,
• Free radicals in enzymatic processes,
• Photochemistry of amino acids and proteins,
• Structural studies of thiols,
• Luminescent polymers,
• Photonic bandgap crystals,
• Mimics of copper-containing enzymes,
• Antioxidants in cancer therapy,
• Dye photophysics and photochemistry,
• Fullerenes,
• Photodynamic therapy (PDT),
• Photochemistry of drugs,
• Nitric oxide reactivity.

The pulse radiolysis line in the SRS Linac Hall
at Daresbury.