Survey of LEPS at TPC

Wen-Chen Chang

Charge

• the flux, energies, and polarizations of the beams that can produce at TPS. Since it will not be tunable, how easy it will be for you change your laser system to get different beam energy?

• the cost for the detector, targets (including polarized ones), laser systems, and electronics,

• how can you compete with MAIMI II, Jlab, and SPring8 as JW asked?

• currently planned exps. on Roper resonance.

Photon Flux

Laser and electron

Laser &

Wavelength

Output Power

Repetition

Rate

Pulse

length

Electron Current & Energy

Photon Flux & Emax

SPring-8 Paladin

355 nm

8W 80MHz 5ps 100mA

8 GeV

700 KHz

2.5 GeV

TPS INDIGO-DUV

193 nm2mW 5KHz 15ns 300mA

3.3 GeV

0.7 KHz

0.8 GeV

TPS AVAI

266 nm3W 100KHz 25ns 300mA

3.3 GeV

1.2 MHz

0.6 GeV

Cost Estimate

• Laser: $200K USD / per unit• Target: un-polarized LH2/LD2 target $20K

/ Polarized HD target $1M• Detector: crystal ball with 4 coverage, m

y guess is $300K – 500K • Electronics: $500K• In total:

– Unpolarized: $1.2 M– Polarized: $2.2 M

LEPS2

• Higher photon flux: 10MHz

• Detectors with large acceptance: move E949 detector system from BNL to Spring-8

• Higher photon energy: 3.5 GeV

MAMIC

Experimental set-up

Tagged photon beam Mainz: m E 800 MeV (Photon 10**8 Hz)

Bonn: 0.6 GeV E 2.9 GeV

Circularly polarized photons

Bremsstrahlung of linearly polarized electrons

Longitudinally polarized Protons/Deuterons

Frozen spin butanol target (Bonn, Bochum, Nagoya)

Mainz: DAPHNE detector (Pavia, Saclay) + forward angle detectors (Pavia, Mainz, Tübingen, Gent)

Bonn: GDH Detector (Erlangen, Tübingen, Gent)

Large acceptance hadron detectors

http://theory.gsi.de/hirschegg/2004/Proceedings/Beck_134.93.132.231_Ftmphirschegghirschegg1example.pdf