TAS workshop 30-31/3/2004

Aspects of recoil-ion - correlations in atomic traps

• A reminder why (V-A , ?S + ?T)

• Energy scales basic setup RIMS

• Precision what to watch out for (LBL).+ versus -

• RIMS issues

• Preliminary setup

TAS workshop 30-31/3/2004

Motivation

Standard Model decay

dud

duu

:pnpn

:pnpp

πi

A J, Z πf

A J, 1Z

neutrino

electron

W±

V - A (V + S) – (A + T)If not SM

Measure - correlations

TAS workshop 30-31/3/2004

Correlations in -decay

• R and D test both TRV• D most potential • R scalar and tensor (EDM, a)• Learn the trade with “a”: ignore spin degrees of freedom

V0 (keV)

Principle idea MOT + RIMS

MeV

detector

MCP-V0 +V00

SM

Not SM

TOF E// very efficient

X,Y E for charged recoils

startstop

TAS workshop 30-31/3/2004

Learn from other experiments

• TRIUMF: 38Km(0+ 0+) aF=0.992(8)(5)promised:?(3)(3)

• LBL: 21Na (3+/2 3+/2) a= 0.524±0.005syst

• systematic error:1. RIMS related 41%2. Unwanted decays (off walls etc.) 26%3. Beta detection 24%

“work on RIMS”

TAS workshop 30-31/3/2004

+ versus - + decay recoil neutral (80%)

21Na (11p + 10n) 21Ne (10p + 11n) + +

80%

19%

3%

0.3%

- decay recoil 1+ : 80% no good case (?) 25Na (11p + 14n) 25Mg (12p + 13n) + -

•Neutrals not efficient•MCP inefficient and tricky+ momentum q-dist•2 background (511 keV)

TAS workshop 30-31/3/2004

RIMS scaled to -decay• Atomic physics

– recoil eV-meV fields V/cm

-decay– recoil 0.1 keV fields kV/cm -energy >> keV

MeVMCP

-V +V0 start

stopTOF E//

TOF + r E

TOF OriginAffects “a” strongly

z

r

-V

recoil

d a

qVE

d

EqVE

aMfE

//////

//

2)(TOF

TAS workshop 30-31/3/2004

Time scales and accuracy

qVEdar

a

a

da

da

qVaEqVMfeVE

daqVMfE

qVE

d

EqVE

aMfE

/)2(

24

2

TOF

TOF

/2/)200(TOF

2/)0(TOF

2)(TOF

//

//////

//

Resolution 1ns2a = 10 cmqV 5 kV 1 eVRange > 400 ns (q=1)Dynamic range > 4 sr < 4 cm

Time focus d=2a

Position focus?Pileup?……….??

Two realizations

Setup at TRIUMF (Behr et al.) for 38mK (t1/2=0.93 s; 0+ 0+)21Na production

Cooling stage

Trapping & detection

Freedman/Vetter setup LBL 21 Na

TAS workshop 30-31/3/2004

Conclusions

• Would have preferred - emitter (background)• RIMS is the trickiest part• Need TOF+2D readout MCP (+ multi hit)• Want 2D + energy of • Simulations needed (position and time focus)• Separate production from trapping (background)• Start working …..