# Presentation: 550111

## Characterization of Main Injector beam parameters

- D. Jensen, G.M. Koizumi, V. Makeev, A. Marchionni      Fermilab
- B.C. Choudhary     CalTech

-  Measurements of transverse and longitudinal beam
-     profiles in MI as a function of beam intensity
-  Additional measurements of momentum spread in P1
-  Plan for the future

## Flying wire in FMI

- A measurement of transverse emittance

- Flattop, intensity ~ 4 1012

- Flattop, intensity ~ 1 1012

## Bunch in a stationary bucket

- t = bunch half-length

- h = harmonic #

- Beam longitudinal emittance  l   E t

**Normalized** ******E/********RF**

## Longitudinal emittance and p/p

## Bunch Length Monitor in FMI

- Bunch length
- ~

- 0=2 fRF

- The Bunch Length Monitor gives the average of the full bunch length (~ 4) over many bunches

## Resistive Wall Monitor in FMI (RTD720)

- Flattop, intensity ~ 4 1012

- Flattop, intensity ~ 1 1012

## Bunch length from Resistive Wall Monitor @flattop before Bunch Rotation

| Intensity | RF (MV) | Bunch half-length
(2)  (ns) | p/p | l   (eVs) |
| --- | --- | --- | --- | --- |
| 1 1012 | 2.8 | 0.95 | 5.6 10-4 | 0.20 |
| 2 1012 | 2.8 | 1.15 | 6.7 10-4 | 0.29 |
| 4 1012 | 2.8 | 1.95 | 1.1 10-3 | 0.83 |

- Observed variations of ~ 10%

## Bunch Length during Bunch Rotation

- Time (t=0.188 ms)

- Average 2 (ns)

- From RTD720

- BLMON

- 2.5 ms

- 2.5 ms

## Bunch Rotation seen with the Resistive Wall Monitor

- Intensity ~ 4 1012

- Different behaviours
- for different bunches

- Phase oscillation with T=5 ms

## A closer look at bunch behaviours during Bunch Rotation

- Time

- Time

- Time

- Time

- Bunch #

- Bunch #

- Bunch Sigma

- Bunch Sigma

- Bunch Phase

- Bunch Phase

## P1 lattice functions

- Beta functions

- Vertical

- Vertical

- Horizontal

- Horizontal

- Eta functions

- 56.0

- 71.6

- 17.2

- 17.7

- -0.10

- -3.87

- -0.13

- -0.17

##  Horizontal MW profiles

- 1 Booster turn

- 10 Booster turns

- MW708

- MW708

- MW702

- MW702

- Measurement of p/p in P1 after Bunch
- Rotation (extracting beam @ minimum of t)

## Horizontal MW position and sigma

| Booster turns | Intensity
(x 1012) | MW702 peak pos (mm) |   MW702 sigma (mm) | MW708 peak  pos (mm) |   MW708 sigma (mm) |
| --- | --- | --- | --- | --- | --- |
| 1 | 0.48 | -2.09 | 1.07 | 4.98 | 2.33 |
| 2 | 0.91 | -2.13 | 1.06 | 5.59 | 2.31 |
| 3 | 1.3 | -2.07 | 1.08 | 5.57 | 2.11 |
| 4 | 1.8 | -2.08 | 1.09 | 5.70 | 2.29 |
| 5 | 2.2 | -2.06 | 1.10 | 6.19 | 2.44 |
| 6 | 2.6 | -2.08 | 1.12 | 6.01 | 2.73 |
| 7 | 3.1 | -2.04 | 1.15 | 6.38 | 3.79 |
| 8 | 3.4 | -2.07 | 1.18 | 6.10 | 3.24 |
| 9 | 3.6 | -2.04 | 1.24 | 6.54 | 3.92 |
| 10 | 3.8 | -2.05 | 1.26 | 6.21 | 4.20 |
| 10 | 3.9 | -2.08 | 1.26 | 6.02 | 4.91 |
| 10 | 4.1 | -2.08 | 1.25 | 6.60 | 3.94 |

## Fit results for transverse emittance and p/p

## Fit results for transverse emittance and p/p

| Intensity
(x 1012) | Vert. Transv. Emittance (95%) | Hor. Transv. Emittance (95%) | p/p (x 10-3)
(95%) |
| --- | --- | --- | --- |
| 0.48 | 20.0 | 16.3 | 1.00 |
| 0.91 | 20.2 | 15.9 | 1.00 |
| 1.3 | 21.5 | 16.6 | 0.86 |
| 1.8 | 20.3 | 16.8 | 0.98 |
| 2.2 | 15.5 | 17.2 | 1.06 |
| 2.6 | 20.1 | 17.9 | 1.22 |
| 3.1 | 19.9 | 18.6 | 1.72 |
| 3.4 | 23.9 | 19.7 | 1.48 |
| 3.6 | 23.8 | 21.7 | 1.86 |
| 3.8 | 24.1 | 22.3 | 1.94 |
| 3.9 | 23.6 | 22.4 | 2.22 |
| 4.1 | 24.9 | 22.2 | 1.82 |

## Plan for the future

-  Measurement program with MI  in single batch mode
-  Complete previous set of measurements
-  Repeat measurement of transverse emittance with flying wires
-  Measure beam emittances @ injection
-  Better understanding of bunch rotation
-  Measurement of momentum spread in P1 extracting beam at the maximum of t (as for NuMI)
-  Measurement of the stability of the central momentum of the beam with and without bunch rotation

## Plan for the future

-  New studies
-  Study losses at Lambertson @ MI52
-  Implement Data Logging of loss monitors, power supply stability in P1, beam stability in MI (BLMON, RPOS, ...)
-  Measurement of beam tails with a crawling wire @ MI52
-       and a scanning target @ Q702
-  Repeat the above measurements with MI in multi-batch mode

## Crawling wire @ MI52

## Scanning target

- The target: tungsten, 100 m thick,
- 1 cm long in the beam direction,
- 10 cm in the transverse direction

## Conclusions

-  Initial measurements indicate beam emittances growing with beam intensity
-  p/p @ 4 1012 protons/batch before bunch rotation  1 10-3 (95%)
-  Both quadrupole and dipole oscillations observed during bunch rotation
-  p/p @ 4 1012 protons/batch with bunch rotation at the minimum of t
-       2 10-3 (95%)
-  Next essential steps
-  measurement of beam tails
-  understanding of beam losses @ extraction
-  A final characterization of the beam from MI requires to set up a test cycle in multi-batch mode