pepper pot monitor for the linac3 itl line

Pepper Pot monitor for the Linac3 ITL Line

MSWG– 13- Aug -2013

F.Roncarolo, A.Ravni

F.Ro

ncar

olo

2

Introduction

SCOPE Provide emittance measurement after the ITL spectrometer

CONSTRAINTS Only space available is diagnostic tank presently hosting slit+ SEM grid

+ Farady cup Beam not round Limited resources in BI

PROPOSED SOLUTION Buy a commercial pepper pot system to be integrated into the

diagnostics tank at the place of the SEM grid

13-A

ug-2

013

F.Ro

ncar

olo

3

Linac 3 - LEBT

Existing Diagnostic Tank

13-A

ug-2

013 Source

ITL

F.Ro

ncar

olo

4

ABP - Request

1. single charge state ion beam from an ECR ion source after the spectrometer

2. intensity: 200 eμA for Pb29+, but could be >1emA for other (lighter) ions3. time structure: 10Hz, 50ms heating pulses with beam extracted, plus ~2ms

afterglow4. beam energy: 2.5 keV/u for interesting beam, other charge states/species

from same potential

5. dimensions of the beam: x = +-1.5 mm, xp = +-130 mrad, y = +-9 mm, yp= +-9.5 mrad,

6. nominal lead beam, 100% beam envelope

7. the system needs to be retractable from the beam line8. the system should be made of UHV compatible components

13-A

ug-2

013

F.Ro

ncar

olo

5

Offers

Detlef Kuchler contacted - Helmholtz-Zentrum Dresden-Rossendorf- Kernfysisch Versneller Instituut (KVI), Groningen, the Netherlands

- PANTECHNIK S.A. , France- Commercialization of KVI system, especially developed to meas. Emittance

at ECR sources front-end- Pepperpot ‘pinhole’ mask, tungsten foil with a vertical row of 20 holes

(20um diameter, 2mm pitch, changeable at the moment of ordering)– X,X’ + Y,Y’ reconstruction by scanning the vertical row along the hor

axis- MCP plate + phosphor screen- CCD camera- Control-Acquisition-Analysis SW

PANTECKNIK offer recognized as the best (D.Kuckler, R.Scrivens, E.Bravin, J-J.Gras, F.Roncarolo) started to investigate integration into existing tank (A.Ravni, BI-ML)

13-A

ug-2

013

F.Ro

ncar

olo

6

PANTECHNIK system

BEAM

Pepper pot plateMCP, PHOSPHOR

Mirror

Camera

13-A

ug-2

013

F.Ro

ncar

olo

7

Integration into existing tank (A.Ravni)

Faraday Cup

SLITPepper Pot

13-A

ug-2

013

F.Ro

ncar

olo

8

Integration into existing tank (A.Ravni)

Variable Diameter

S-Shaped

Faraday Cup

SLIT

Faraday Cup

SLIT

Pepper Pot

Pepper Pot

This tank design

• verified with main workshop• allows keeping SLIT and FC

mechanisms as existing

13-A

ug-2

013

F.Ro

ncar

olo

9

Integration into existing tank (A.Ravni)

Tank modifications w.r.t. existing one- Slit moved forward of 50 mm (maximum allowed, A.Lombardi)- Tank diameter reduced of 46 mm (300 254 mm)- Tank length increased of 70 mm (310 380 mm) shorter bellow on 1

side) - to avoid interference w. Pepper Pot

- FC side diameter opening changed - Slit side tank with S-shape (angle)

Still to be decided: interconnection to upstream pipe, being discussed with Vacuum (J.Hansen), to avoid having bellow directly soldered on pipe (as proposed by BI-ML)

13-A

ug-2

013

F.Ro

ncar

olo

10

Timing and gating13

-Aug

-201

3

Linac3 requirements: 50ms pulse + 2 ms (max) afterglow, 10Hz rep. rate- want to sample afterglow emittance with 100us (max) sampling rate

Pantechnik proposed:-Camera: SONY XCL-U1000

shutter trigger rate 15Hz (max)shutter gate length from 100us to 66ms

-Phosphor: P431.2 ms decay time

So, we looked at alternative phosphors-R42, P47 fast enough-P47 better radiation hard

F.Ro

ncar

olo

11

13-A

ug-2

013

Camera sensitivity matches better R42 than P47, but P47 has twice the emissivity (see table previous slide)

Conclusion: Pantechnik accepted to provide P47 for same price as P43

F.Ro

ncar

olo

12

Conclusions

Commercial Pepper Pot Order approved by purchasing officer on Aug 9th Design of new tank finished

- Slit and FC as they are- If approved by all concerned people

- Launch tank fabrication Delays

- From Pantechnik offer: 5 month (Aug. Excluded) - Need to follow up to ensure reception and installation for ~Feb2014

Costs- 90kEu - Tank costs to be estimated

Operation&Control- It is not foreseen to integrate the system into the CO infrastructure- System to be used on stand-alone PC (control + data processing via Labview provided by

Pantechnik) ‘VIA fellow’ (shared by ABP and BI), from end of 2013, supposed to look also

into emittance measurements at Linac3

13-A

ug-2

013

F.Ro

ncar

olo

13

13-A

ug-2

013