1. Application of Diamond Sensors at FLASH M.-E. Castro-Carballo, H. Henschel, A. Ignatenko, W. Lange, O. Novgorodova, W. Lohmann, R. Schmidt, S. Schuwalow DESY, Zeuthen June 29, 2009

2. 22 Overview  FLASH overview  Motivation for BHM placement  BHM  Outlook  Sensors  Test at PITZ  Results  Summary

3. 3 FLASH overview 1GeV maximum electron beam energy Wavelength down to 6.5 nm 10 fs pulses Peak current 1-2 kA High-gain Free Electron Laser VUV and soft X-ray regime Self-Amplified Spontaneous Emission (SASE) mode

4. 4 Motivation for BHM placement BPM9 Stripline BPM15 Button WINDOW with Ti-chamber SWEEPER RD13 (HSK) QUAD Q10 (QC) QUAD Q11 (QC) Chamber with pump port & bellow DUMP Dump Vacuum Section 2879mm STEERER, H7  to bend plane (CV) DIPOLE + Trim D6 (TDC) FLASH beam dump line Vacuum leak New beam position diagnostic tools are needed 4

5. 5 Outlook 5 Beam Halo Monitor Electron beam pipe BHM sensors Air BPM

6. 66 Sensors 1. pCVD diamond produced by Diamond Detectors Ltd. Dimensions 10×10×0.3 mm 3 Metallization: 50/50/200 nm Ti/Pt/Au 2. Single crystal sapphire (Al 2 O 3 ) produced by CRYSTAL GmbH Dimensions 10×10×0.3 mm 3 Metallization: 50/50/200 nm Al/Ti/Au The sensors will be operated like solid-state ionization chambers

7. 77 Test at PITZ pCVD diamond Dimensions 12×12×0.5 mm 3 Metallization: 10×10 mm 2 Ti/Pt/Au WS2 0.5 m 3 m 25 m 45 m

8. 8 Plan of measurements 1. Electromagnetic Impact (EMI) investigation Sensor without bias. Scan over different bunch charges at parking position; x-position scans at certain bunch intensity. 2. Signal size measurements Biased sensor in the beam center. Measurements of the signal size over bunch intensity at different bias voltages. Scans of the beam profile (focused and unfocused beam).

9. 9 No bias, parking position No bias, x=-5mm 100V bias voltage, parking position Bunch charge 100pC Results

10. 10 Beam profile on High2scr1 Imain=295A Imain=345A xRMS=0.93 mm yRMS=1.30 mm xRMS=3.36 mm yRMS=3.29 mm appr. position and dimensions of the diamond sensor

11. 1111 Imain=295A Imain=345A Signal from the diamond sensor Bunch train trigger Signal

12. 12

13. 13 Expected charge produced in diamond by 10 pC beam ~ 230 nC 1 a.u. ~ 1 nC

14. 14 Summary 1. Tests with 1 pCVD diamond sensor were carried out at PITZ (Photo Injector Test facility Zeuthen). 2. The diamond was operated in the bunch charge range 1 pC to 1 nC 3. Clear dependence of the signal on the bunch charge was observed 4. Beam profiles for defocused and focused beam were measured 5. EMI signals for unbiased sensor were small in comparison with the signals from biased sensor 6. 4 pCVD diamonds and 4 artificial sapphires will be operated in real accelerator conditions at FLASH